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.

A117469 The largest part summed over all partitions of n in which every integer from the smallest part to the largest part occurs.

Original entry on oeis.org

1, 3, 6, 9, 13, 19, 24, 30, 42, 49, 61, 79, 92, 110, 144, 162, 195, 242, 278, 332, 405, 463, 546, 656, 759, 882, 1049, 1205, 1399, 1655, 1887, 2181, 2546, 2909, 3361, 3880, 4422, 5069, 5831, 6641, 7566, 8666, 9818, 11159, 12730, 14376, 16281, 18465, 20828
Offset: 1

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Author

Emeric Deutsch, Mar 19 2006

Keywords

Comments

a(n)=Sum(k*A117468(n,k),k=1..n).

Examples

			a(5)=13 because in the 5 (=A034296(5)) partitions in which every integer from the smallest to the largest part occurs, namely [5],[3,2],[2,2,1],[2,1,1,1] and [1,1,1,1,1], the sum of the largest parts is 5+3+2+2+1=13.
		

Crossrefs

Programs

  • Maple
    g:=sum(x^j*product(1+x^i,i=1..j-1)*(1+(1-x^j)*sum(x^i/(1+x^i),i=1..j-1))/(1-x^j)^2,j=1..70): gser:=series(g,x=0,60): seq(coeff(gser,x,n),n=1..55);

Formula

G.f.=sum(x^j*product(1+x^i, i=1..j-1)*[1+(1-x^j)sum(x^i/(1+x^i), i=1..j-1)]/(1-x^j)^2, j=1..infinity) (obtained by taking the derivative with respect to t of the g.f. G(t,x) of A117468 and setting t=1).