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.

A348537 Number of partitions of n into 3 parts whose largest part divides n.

Original entry on oeis.org

0, 0, 1, 1, 0, 2, 0, 2, 1, 2, 0, 4, 0, 3, 1, 4, 0, 5, 0, 5, 1, 5, 0, 7, 0, 6, 1, 7, 0, 8, 0, 8, 1, 8, 0, 10, 0, 9, 1, 10, 0, 11, 0, 11, 1, 11, 0, 13, 0, 12, 1, 13, 0, 14, 0, 14, 1, 14, 0, 16, 0, 15, 1, 16, 0, 17, 0, 17, 1, 17, 0, 19, 0, 18, 1, 19, 0, 20, 0, 20, 1, 20, 0, 22, 0
Offset: 1

Views

Author

Wesley Ivan Hurt, Oct 21 2021

Keywords

Crossrefs

Cf. A069905.

Programs

  • Mathematica
    Array[Sum[Sum[(1 - Ceiling[#/(# - i - j)] + Floor[#/(# - i - j)]), {i, j, Floor[(# - j)/2]} ], {j, Floor[#/3]} ] &, 85] (* Michael De Vlieger, Oct 21 2021 *)
  • PARI
    A348537(n) = sum(j=1,(n\3), sum(i=j,((n-j)\2), (1 - ceil(n/(n-i-j)) + floor(n/(n-i-j))))); \\ Antti Karttunen, Feb 18 2023

Formula

a(n) = Sum_{j=1..floor(n/3)} Sum_{i=j..floor((n-j)/2)} (1 - ceiling(n/(n-i-j)) + floor(n/(n-i-j))).