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.

A241870 Number of compositions of n such that the smallest part has multiplicity ten.

Original entry on oeis.org

1, 0, 11, 11, 77, 143, 495, 1133, 3058, 7271, 17777, 41580, 96701, 220187, 495528, 1099626, 2412927, 5236308, 11251449, 23952841, 50556265, 105852923, 219975999, 453933348, 930544912, 1895736986, 3839424644, 7732852963, 15492659226, 30884561378, 61276442019
Offset: 10

Views

Author

Joerg Arndt and Alois P. Heinz, Apr 30 2014

Keywords

Comments

Conjecture: Generally, for k > 0 is column k of A238342 asymptotic to n^k * ((1+sqrt(5))/2)^(n-2*k-1) / (5^((k+1)/2) * k!). - Vaclav Kotesovec, May 02 2014

Crossrefs

Column k=10 of A238342.

Programs

  • Maple
    b:= proc(n, s) option remember; `if`(n=0, 1,
          `if`(nadd(coeff(p, x, i)*binomial(i+k, k),
           i=0..degree(p)))(b(n-j*k, j+1)), j=1..n/k)
        end:
    seq(a(n), n=10..40);
  • Mathematica
    b[n_, s_] := b[n, s] = If[n == 0, 1, If[n < s, 0, Expand[Sum[b[n - j, s]*x, {j, s, n}]]]]; a[n_] := With[{k = 10}, Sum[Function[{p}, Sum[Coefficient[p, x, i] * Binomial[i + k, k], {i, 0, Exponent[p, x]}]][b[n - j*k, j + 1]], {j, 1, n/k}]]; Table[ a[n], {n, 10, 40}] (* Jean-François Alcover, Feb 09 2015, after Maple *)

Formula

a(n) ~ n^10 * ((1+sqrt(5))/2)^(n-21) / (5^(11/2) * 10!). - Vaclav Kotesovec, May 02 2014