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.

A079308 For a partition P of a positive integer, let f(P) be the product of k+1, over all parts k in P. Let a(n,r) be the sum of f(P) over all partitions P of n with smallest part r. Sequence gives table of a(n,r) for 1 <= r <= n, in the order a(1,1); a(2,1), a(2,2); a(3,1), a(3,2), a(3,3); ...

Original entry on oeis.org

2, 4, 3, 14, 0, 4, 36, 9, 0, 5, 100, 12, 0, 0, 6, 236, 42, 16, 0, 0, 7, 602, 54, 20, 0, 0, 0, 8, 1368, 195, 24, 25, 0, 0, 0, 9, 3242, 246, 92, 30, 0, 0, 0, 0, 10, 7240, 759, 112, 35, 36, 0, 0, 0, 0, 11, 16386, 1134, 232, 40, 42, 0, 0, 0, 0, 0, 12, 35692, 2859, 528, 170, 48, 49, 0, 0, 0, 0, 0, 13
Offset: 1

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Author

Alford Arnold, Feb 09 2003

Keywords

Examples

			The partitions with minimal part 3 begin 3, 3+3, 4+3, 5+3, 6+3, 3+3+3, ... which yield the following values of f: 4, 16, 20, 24, 28, 64, ... therefore the 3rd column of our table begins 4,0,0,16,20,24,(28+64)=92,...
Triangle a(n,r) begins:
:    2;
:    4,   3;
:   14,   0,   4;
:   36,   9,   0,  5;
:  100,  12,   0,  0,  6;
:  236,  42,  16,  0,  0, 7;
:  602,  54,  20,  0,  0, 0, 8;
: 1368, 195,  24, 25,  0, 0, 0, 9;
: 3242, 246,  92, 30,  0, 0, 0, 0, 10;
: 7240, 759, 112, 35, 36, 0, 0, 0,  0, 11;
		

Crossrefs

Cf. A074139, A074141 (row sums).

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          `if`(k>n, 0, b(n, k+1) +(k+1)*b(n-k, k)))
        end:
    a:= (n, k)-> b(n,k)-b(n, k+1):
    seq(seq(a(n, k), k=1..n), n=1..12);  # Alois P. Heinz, May 22 2015
  • Mathematica
    a[n_, r_] := Which[r>n, 0, r==n, n+1, True, a[n, r]=(r+1)Sum[a[n-r, s], {s, r, n-r}]]; Flatten[Table[a[n, r], {n, 1, 12}, {r, 1, n}]]

Extensions

Edited by Dean Hickerson, Feb 11 2003
Offset changed to 1 by Alois P. Heinz, May 22 2015