ChrisR - MATLAB Cody - MATLAB Central

ChrisR

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Problem 60846. List e-perfect numbers

Created by: ChrisR

Tags number theory, sequence

3

Solvers

66

Size

3

Solvers

66

Size

Problem 60845. Sum powers of e-divisors

Created by: ChrisR

Tags primes, number theory, sequence

4

Solvers

65

Size

4

Solvers

65

Size

Problem 60844. Count the e-divisors of an integer

Created by: ChrisR

Tags primes, number theory, factorization

4

Solvers

39

Size

4

Solvers

39

Size

Problem 60843. Determine the e-divisors of an integer

Created by: ChrisR

Tags primes, number theory, factorization

4

Solvers

48

Size

4

Solvers

48

Size

Problem 60839. List the notes of a major scale

Created by: ChrisR

Tags music, pattern, scales

4

Solvers

67

Size

4

Solvers

67

Size

Problem 60830. Compute the saturation concentration for dissolved oxygen in water

Created by: ChrisR

Tags ce 5720, streeter-phelps, curve fit

4

Solvers

60

Size

4

Solvers

60

Size

Problem 60788. Construct the number counts sequence

Created by: ChrisR

Tags sequence, inventory

4

Solvers

62

Size

4

Solvers

62

Size

Problem 60787. List the first of three consecutive square-free numbers

Created by: ChrisR

Tags factor, sequence, mobius

4

Solvers

49

Size

4

Solvers

49

Size

Problem 60786. Count the primes resulting from changing one digit of a number

Created by: ChrisR

Tags primes, strings, sequence

4

Solvers

67

Size

4

Solvers

67

Size

Problem 60785. Solve an easy binary puzzle

Created by: ChrisR

Tags matrix manipulation, puzzle, strfind

4

Solvers

89

Size

4

Solvers

89

Size

Problem 60784. Indicate how the Prague astronomical clock strikes the hours

Created by: ChrisR

Tags strings, sum, sequence

5

Solvers

49

Size

5

Solvers

49

Size

Problem 60783. Convert integers from base 10 to proper primary notation

Created by: ChrisR

Tags conversion, number theory

3

Solvers

264

Size

3

Solvers

264

Size

Problem 60782. Convert integers from primary notation to base 10

Created by: ChrisR

Tags conversion, number theory

7

Solvers

30

Size

7

Solvers

30

Size

Problem 60781. Express integers in negabinary

Created by: ChrisR

Tags base, number theory, sequence

5

Solvers

13

Size

5

Solvers

13

Size

Problem 60780. Play Hocus Focus

Created by: ChrisR

Tags matrix manipulation, games

9

Solvers

23

Size

9

Solvers

23

Size

Problem 60778. Complete hydraulic geometry relations

Created by: ChrisR

Tags fluid mechanics, rivers

7

Solvers

34

Size

7

Solvers

34

Size

Problem 60765. Identify points inside a Reuleaux triangle

Created by: ChrisR

Tags geometry

4

Solvers

33

Size

4

Solvers

33

Size

Problem 60764. Determine whether a number is a Ludic prime

Created by: ChrisR

Tags primes, sequence, sieve

5

Solvers

60

Size

5

Solvers

60

Size

Problem 60760. Find the closest canyon prime

Created by: ChrisR

Tags primes, sequence, anniversary

4

Solvers

81

Size

4

Solvers

81

Size

Problem 60758. List composite numbers that do not contain their prime factors as substrings

Created by: ChrisR

Tags primes, strings, sequence

5

Solvers

81

Size

5

Solvers

81

Size

Problem 60751. List the partitions of an integer

Created by: ChrisR

Tags number theory

5

Solvers

63

Size

5

Solvers

63

Size

Problem 60749. Compute the dispersion coefficient

Created by: ChrisR

Tags integration, river mixing, shear dispersion

4

Solvers

30

Size

4

Solvers

30

Size

Problem 60748. Extend the digamma function to negative arguments

Created by: ChrisR

Tags reflection, special functions

4

Solvers

26

Size

4

Solvers

26

Size

Problem 60747. Describe n from right to left

Created by: ChrisR

Tags string, sequence

7

Solvers

55

Size

7

Solvers

55

Size

Problem 60746. List Ormiston prime pairs

Created by: ChrisR

Tags primes, mod, sequence

5

Solvers

48

Size

5

Solvers

48

Size

Problem 60739. Explore the twin prime Goldbach conjecture

Created by: ChrisR

Tags primes, numberphile

5

Solvers

49

Size

5

Solvers

49

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Problem 60733. Find the closest geyser prime

Created by: ChrisR

Tags primes, sequence, anniversary

6

Solvers

57

Size

6

Solvers

57

Size

Problem 60727. Remove the diagonal of a square matrix

Created by: ChrisR

Tags matrix manipulation, diagonal

13

Solvers

25

Size

13

Solvers

25

Size

Problem 60633. Sum the reciprocals of polygonal numbers

Created by: ChrisR

Tags special functions, partial fractions

4

Solvers

33

Size

4

Solvers

33

Size

Problem 60581. List primes of the form xy+z

Created by: ChrisR

Tags primes, number theory, sequence

9

Solvers

38

Size

9

Solvers

38

Size

Problem 60571. Find polygonal numbers that are Blum integers

Created by: ChrisR

Tags number theory, sequence, semiprime

6

Solvers

63

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6

Solvers

63

Size

Problem 60561. Determine whether a number is a Blum integer

Created by: ChrisR

Tags primes, number theory, sequence

7

Solvers

31

Size

7

Solvers

31

Size

Problem 60541. Compute the number of squares a knight can reach after n moves

Created by: ChrisR

Tags chess, sequence, recurrence

6

Solvers

30

Size

6

Solvers

30

Size

Problem 60516. Compute the totient summatory function

Created by: ChrisR

Tags number theory, sequence

5

Solvers

45

Size

5

Solvers

45

Size

Problem 60486. Compute Farey sequences

Created by: ChrisR

Tags fractions, sequence, mediant

8

Solvers

58

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8

Solvers

58

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Problem 60456. Compute a sum

Created by: ChrisR

Tags sum, j pi maths, partial fractions

7

Solvers

29

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7

Solvers

29

Size

Problem 60411. Compute a sequence with the whyphi sieve

Created by: ChrisR

Tags sequence, sieve, triangular

3

Solvers

49

Size

3

Solvers

49

Size

Problem 60406. Alert a city about a spill

Created by: ChrisR

Tags datetime, river mixing, fzero

4

Solvers

126

Size

4

Solvers

126

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Problem 60401. Find primes and integers that solve an equation

Created by: ChrisR

Tags number theory, wilsons theorem, j pi maths

7

Solvers

53

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7

Solvers

53

Size

Problem 60351. List the smallest numbers with n distinct prime factors

Created by: ChrisR

Tags sequence, 46054, 46057

6

Solvers

41

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6

Solvers

41

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Problem 60346. Classify numbers as abundant, deficient, or perfect

Created by: ChrisR

Tags number theory, sequence

6

Solvers

56

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6

Solvers

56

Size

Problem 60336. Determine whether a property description closes

Created by: ChrisR

Tags geometry, trigonometry, surveying

5

Solvers

108

Size

5

Solvers

108

Size

Problem 60331. Compute the area of a Q

Created by: ChrisR

Tags geometry, numberphile, quadrature

6

Solvers

20

Size

6

Solvers

20

Size

Problem 60311. Travel a path

Created by: ChrisR

Tags strings, trigonometry, movement

4

Solvers

49

Size

4

Solvers

49

Size

Problem 60306. Add non-triangular numbers

Created by: ChrisR

Tags sum, algebra, sequence

12

Solvers

13

Size

12

Solvers

13

Size

Problem 60301. Compute the area of a lune

Created by: ChrisR

Tags geometry, trigonometry, circles

7

Solvers

73

Size

7

Solvers

73

Size

Problem 60291. Minimize a quadratic function

Created by: ChrisR

Tags minimization, dr barker

7

Solvers

80

Size

7

Solvers

80

Size

Problem 59981. Compute the Ramanujan tau function

Created by: ChrisR

Tags number theory, sequence, special functions

2

Solvers

58

Size

2

Solvers

58

Size

Problem 59871. List the segmented numbers

Created by: ChrisR

Tags number theory, cumsum, sequence

5

Solvers

42

Size

5

Solvers

42

Size

Problem 59861. List the ways to write 1/n as the sum of two unit fractions

Created by: ChrisR

Tags number theory

7

Solvers

30

Size

7

Solvers

30

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1 – 50 of 298