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A115604 Triangle read by rows: T(n,k) is the number of partitions of n into odd parts in which the smallest part occurs k times (1<=k<=n). 0

%I #3 Mar 30 2012 17:36:07

%S 1,0,1,1,0,1,1,0,0,1,1,1,0,0,1,1,1,1,0,0,1,2,1,0,1,0,0,1,2,1,1,0,1,0,

%T 0,1,2,1,2,1,0,1,0,0,1,3,2,1,1,1,0,1,0,0,1,3,3,1,1,1,1,0,1,0,0,1,4,2,

%U 2,2,1,1,1,0,1,0,0,1,5,3,2,2,1,1,1,1,0,1,0,0,1,5,4,3,2,2,1,1,1,1,0,1,0,0,1

%N Triangle read by rows: T(n,k) is the number of partitions of n into odd parts in which the smallest part occurs k times (1<=k<=n).

%C Row sums yield A000009. T(n,1)=A087897(n+2). Sum(k*T(n,k),k=1..n)=A092268(n).

%F G.f.=G(t,x)=sum(tx^(2k-1)/[(1-tx^(2k-1))product(1-x^(2i-1), i=k+1..infinity)], k=1..infinity).

%e T(14,2)=4 because we have [9,3,1,1],[7,7],[7,5,1,1] and [3,3,3,3,1,1].

%e Triangle starts:

%e 1;

%e 0,1;

%e 1,0,1;

%e 1,0,0,1;

%e 1,1,0,0,1;

%e 1,1,1,0,0,1;

%e 2,1,0,1,0,0,1;

%p g:=sum(t*x^(2*k-1)/(1-t*x^(2*k-1))/product(1-x^(2*i-1),i=k+1..40),k=1..40): gser:=simplify(series(g,x=0,55)): for n from 1 to 15 do P[n]:=expand(coeff(gser,x^n)) od: for n from 1 to 15 do seq(coeff(P[n],t^j),j=1..n) od; # yields sequence in triangular form

%Y Cf. A000009, A087897, A092268, A117408.

%K nonn,tabl

%O 1,22

%A _Emeric Deutsch_, Mar 13 2006

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)