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A096812
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Forwards row convergent of triangle A096811, in which A096811(n,k) equals the k-th term of the convolution of the two prior rows indexed by (n-k) and (k-2).
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4
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1, 1, 1, 2, 4, 8, 16, 34, 72, 156, 336, 746, 1652, 3696, 8330, 18816, 42904, 98166, 225148, 518386, 1199966, 2778270, 6472492, 15097226, 35311946, 82744656, 194406728, 457526278, 1078889548, 2549790238, 6034719500, 14305107700, 33965903292, 80747360636, 192219095518, 458252713872, 1093494859572, 2613290156486, 6251109118574, 14970041423150
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OFFSET
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0,4
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COMMENTS
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LINKS
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FORMULA
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a(0)=a(1)=1; for n>1, a(n) = Sum_{k=0..n-2} A096811(n-2, n-k-2)*a(k+1).
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PROG
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(PARI) {A096811(n, k)=if(n<k || k<0, 0, if(k<=1 || k==n, 1, sum(j=1, k-1, A096811(n-k, j)*A096811(k-2, k-j-1))))} \ {a(n)=if(n<0, 0, if(n<=1, 1, sum(k=0, n-2, T(n-2, n-k-2)*a(k+1))))}
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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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