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.

A117145 Triangle read by rows: T(n,k) is the number of partitions of n into parts of the form 2^j-1, j=1,2,... and having k parts (n>=1, k>=1). Partitions into parts of the form 2^j-1, j=1,2,... are called s-partitions.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 2, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 0, 0, 0, 2, 0, 2, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 0, 1
Offset: 1

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Author

Emeric Deutsch, Mar 06 2006

Keywords

Comments

Row sums yield A000929. sum(k*T(n,k),k=1..n)=A117146(n).

Examples

			T(9,3)=2 because we have [7,1,1] and [3,3,3].
		

Crossrefs

Programs

  • Maple
    g:=-1+1/product(1-t*x^(2^k-1),k=1..10): gser:=simplify(series(g,x=0,20)): for n from 1 to 19 do P[n]:=sort(coeff(gser,x^n)) od: for n from 1 to 19 do seq(coeff(P[n],t^j),j=1..n) od; # yields sequence in triangular form

Formula

G.f.: G(t,x) = -1+1/product(1-tx^(2^k-1), k=1..infinity).