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A113990
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Column 1 of triangle A113988, which is the matrix square of A113983: a(n) = [A113983^2](n+1,1).
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4
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1, 4, 12, 36, 116, 416, 1680, 7656, 39256, 225348, 1439868, 10179116, 79153484, 673262240, 6231517920, 62461031920, 675005395152, 7832909636740, 97238472215564, 1286967352638292, 18102901048062404, 269852768731391808
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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PROG
| (PARI) {a(n)=local(A, B); A=Mat(1); for(m=2, n+2, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3|j==1|j==i, B[i, j]=1, B[i, j]=A[i-1, j-1]+(A^2)[i-2, j-1] ); )); A=B); (A^2)[n+2, 2]}
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CROSSREFS
| Cf. A113988, A113989 (column 0), A113991 (column 2), A113992 (column 3).
Sequence in context: A000781 A192205 A055395 * A192010 A056383 A052643
Adjacent sequences: A113987 A113988 A113989 * A113991 A113992 A113993
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KEYWORD
| nonn
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AUTHOR
| Paul D. Hanna (pauldhanna(AT)juno.com), Nov 12 2005
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