cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A286238 Triangle A286239 reversed.

Original entry on oeis.org

1, 2, 1, 4, 0, 3, 7, 0, 2, 3, 11, 0, 0, 0, 10, 16, 0, 0, 4, 5, 3, 22, 0, 0, 0, 0, 0, 21, 29, 0, 0, 0, 7, 0, 5, 10, 37, 0, 0, 0, 0, 0, 8, 0, 21, 46, 0, 0, 0, 0, 11, 0, 0, 14, 10, 56, 0, 0, 0, 0, 0, 0, 0, 0, 0, 55, 67, 0, 0, 0, 0, 0, 16, 0, 12, 8, 5, 10, 79, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 78, 92, 0, 0, 0, 0, 0, 0, 22, 0, 0, 0, 0, 27, 21, 106, 0, 0, 0, 0, 0, 0, 0, 0, 0, 17, 0, 19, 0, 36
Offset: 1

Views

Author

Antti Karttunen, May 06 2017

Keywords

Comments

See A286239.

Examples

			The first fifteen rows of triangle:
    1,
    2, 1,
    4, 0, 3,
    7, 0, 2, 3,
   11, 0, 0, 0, 10,
   16, 0, 0, 4,  5, 3,
   22, 0, 0, 0,  0,  0, 21,
   29, 0, 0, 0,  7,  0,  5, 10,
   37, 0, 0, 0,  0,  0,  8,  0, 21,
   46, 0, 0, 0,  0, 11,  0,  0, 14, 10,
   56, 0, 0, 0,  0,  0,  0,  0,  0,  0, 55,
   67, 0, 0, 0,  0,  0, 16,  0, 12,  8,  5, 10,
   79, 0, 0, 0,  0,  0,  0,  0,  0,  0,  0,  0, 78,
   92, 0, 0, 0,  0,  0,  0, 22,  0,  0,  0,  0, 27, 21,
  106, 0, 0, 0,  0,  0,  0,  0,  0,  0, 17,  0, 19,  0, 36
		

Crossrefs

Transpose: A286239 (triangle reversed).

Programs

  • Python
    from sympy import totient
    def T(n, m): return ((n + m)**2 - n - 3*m + 2)//2
    def t(n, k): return 0 if n%k!=0 else T(totient(n//k), k)
    for n in range(1, 21): print([t(n, k) for k in range(1, n + 1)][::-1]) # Indranil Ghosh, May 09 2017
  • Scheme
    (define (A286238 n) (A286239tr (A002024 n) (A038722 n))) ;; For A286239tr see A286239.
    

Formula

T(n,k) = A286239(k,n).