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Search: id:A109319
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| A109319 |
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Row sums of triangle T=A109316 where T(n,k) = [T^2](n-1,k) + [T^2](n-2,k-1) and T^2 is the matrix square of A109316. |
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+0
4
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| 1, 2, 5, 15, 55, 235, 1119, 5775, 31663, 182087, 1087927, 6706823, 42433735, 274403575, 1807700679, 12099813111, 82113733447, 563992581079, 3914861387495, 27429176467703, 193781828188615, 1379223584026967
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OFFSET
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0,2
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PROGRAM
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(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, if(i==2, B[i, j]=1, B[i, j]=(A^2)[i-1, j]+if(j>1, (A^2)[i-2, j-1]))); )); A=B); return(sum(k=0, n, A[n+1, k+1]))}
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CROSSREFS
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Cf. A109316 (triangle), A109317 (column 0), A109318 (column 2).
Sequence in context: A051295 A009383 A104429 this_sequence A059219 A137533 A121392
Adjacent sequences: A109316 A109317 A109318 this_sequence A109320 A109321 A109322
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Jul 07 2005
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