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.

A266691 Number of partitions of n with product of multiplicities of parts equal to 8.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 3, 2, 5, 4, 10, 9, 17, 20, 25, 31, 47, 53, 71, 89, 109, 138, 171, 205, 257, 317, 375, 461, 557, 664, 792, 962, 1124, 1352, 1596, 1878, 2215, 2621, 3042, 3584, 4180, 4862, 5658, 6593, 7598, 8826, 10190, 11730, 13516, 15562, 17811
Offset: 0

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Author

Emeric Deutsch and Alois P. Heinz, Jan 02 2016

Keywords

Examples

			a(8) = 2: [1,1,1,1,1,1,1,1], [1,1,1,1,2,2].
a(10) = 3: [1,1,1,1,1,1,1,1,2], [1,1,2,2,2,2], [1,1,1,1,3,3].
a(12) = 5: [1,1,1,1,2,3,3], [1,1,2,2,3,3], [1,1,1,1,1,1,1,1,4], [1,1,1,1,2,2,4], [1,1,1,1,4,4].
		

Crossrefs

Column k=8 of A266477.

Programs

  • Maple
    b:= proc(n, i, p) option remember; `if`(i*(p+(i-1)/2)0, 0, (h->
           b(h, min(h, i-1), p/j))(n-i*j)), j=1..min(p, n/i))))
        end:
    a:= b(n$2, 8):
    seq(a(n), n=0..65);
  • Mathematica
    b[n_, i_, p_] := b[n, i, p] = If[i*(p + (i - 1)/2) < n, 0, If[n == 0, If[p == 1, 1, 0], b[n, i - 1, p] + Sum[If[Mod[p, j] > 0, 0, Function[h, b[h, Min[h, i - 1], p/j]][n - i*j]], {j, 1, Min[p, n/i]}]]];
    a[n_] := b[n, n, 8];
    Table[a[n], {n, 0, 65}] (* Jean-François Alcover, May 01 2018, translated from Maple *)

Formula

a(n) ~ c * exp(Pi*sqrt(n/3)) * n^(3/4), where c = 0.0012263686774... - Vaclav Kotesovec, May 24 2018