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A116683
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Triangle read by rows: T(n,k) is the number of partitions of n into distinct parts, in which the sum of the even parts is k (n>=0, 0<=k<=n).
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2
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1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 2, 1, 0, 1, 0, 1, 0, 2, 2, 0, 1, 0, 1, 0, 0, 0, 2, 2, 0, 1, 0, 1, 0, 2, 0, 2, 2, 0, 2, 0, 1, 0, 2, 0, 0, 0, 3, 2, 0, 2, 0, 1, 0, 2, 0, 2, 0, 3, 3, 0, 2, 0, 2, 0, 2, 0, 2, 0, 0, 0, 4, 3, 0, 2, 0, 2, 0, 2, 0, 2, 0, 3, 0, 4, 3, 0, 3, 0, 2, 0, 4
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OFFSET
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0,25
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COMMENTS
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Row 2n-1 has 2n-1 terms; row 2n has 2n+1 terms. Row sums yield A000009. T(n,0)=A000700(n). Columns 2n-1 contain only 0's. Sum(k*T(n,k), k=0..n)=A116684(n).
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LINKS
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FORMULA
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G.f.=product((1+x^(2j-1))(1+(tx)^(2j)), j=1..infinity).
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EXAMPLE
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T(9,6)=2 because we have [6,3] and [4,3,2].
Triangle starts:
1;
1;
0,0,1;
1,0,1;
1,0,0,0,1;
1,0,1,0,1;
1,0,1,0,0,0,2
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MAPLE
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g:=product((1+x^(2*j-1))*(1+(t*x)^(2*j)), j=1..30): gser:=simplify(series(g, x=0, 20)): P[0]:=1: for n from 1 to 14 do P[n]:=sort(coeff(gser, x^n)) od: for n from 0 to 14 do seq(coeff(P[n], t, j), j=0..2*floor(n/2)) od; # yields sequence in triangular form
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CROSSREFS
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KEYWORD
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nonn,tabf
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AUTHOR
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STATUS
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approved
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