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.

A327557 Total number of colors in all colored integer partitions of n using all colors of an initial interval of the color palette such that all parts have different color patterns and a pattern for part i has i colors in (weakly) increasing order.

Original entry on oeis.org

0, 1, 5, 29, 173, 1129, 7933, 59757, 480389, 4102233, 37059485, 352891285, 3530465753, 37001007337, 405191214949, 4625525704837, 54929552638957, 677283511701937, 8655757492783861, 114479050583748677, 1564613481125976373, 22068492671782019793
Offset: 0

Views

Author

Alois P. Heinz, Sep 16 2019

Keywords

Crossrefs

Cf. A327116.

Programs

  • Maple
    C:= binomial:
    b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
          b(n-i*j, min(n-i*j, i-1), k)*C(C(k+i-1, i), j), j=0..n/i)))
        end:
    a:= n-> add(k*add(b(n$2, i)*(-1)^(k-i)*C(k, i), i=0..k), k=0..n):
    seq(a(n), n=0..23);
  • Mathematica
    c = Binomial;
    b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i < 1, 0, Sum[b[n - i*j, Min[n - i*j, i - 1], k] c[c[k + i - 1, i], j], {j, 0, n/i}]]];
    a[n_] := Sum[k Sum[b[n, n, i] (-1)^(k - i) c[k, i], {i, 0, k}], {k, 0, n}];
    a /@ Range[0, 23] (* Jean-François Alcover, Dec 16 2020, after Alois P. Heinz *)

Formula

a(n) = Sum_{k=1..n} k * A327116(n,k).