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A027109
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a(n) = Sum_{k=0..n} T(n,k) * T(n,n+k), with T given by A027082.
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0
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1, 2, 6, 29, 131, 619, 3013, 14854, 73996, 372023, 1883369, 9591012, 49091034, 252371780, 1302419484, 6744389329, 35031370911, 182457629783, 952674694705, 4985494458892, 26143834054498, 137358293523986, 722938114992478
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OFFSET
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0,2
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LINKS
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MATHEMATICA
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T[_, 0] = T[_, 1] = T[_, 2] = 1;
T[n_, k_] := T[n, k] = If[k < 2n, T[n-1, k-3] + T[n-1, k-2] + T[n-1, k-1], T[n-1, 2n-3] + T[n-1, 2n-2]];
a[n_] := Sum[T[n, k] T[n, n+k], {k, 0, n}];
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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