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Search: id:A102087
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| A102087 |
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Column 1 of triangular matrix A102086, which shifts upward to exclude the main diagonal under matrix square. |
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+0
6
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| 0, 2, 4, 20, 156, 1664, 22684, 378572, 7504640, 172785512, 4540756252, 134330010172, 4423176368332, 160596613105384, 6378859853838480, 275308217428662672, 12836003750434047344, 643227594173121801096
(list; graph; listen)
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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=matrix(2, 2), B); A[1, 1]=1; for(m=2, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=j, if(j==1, B[i, j]=(A^2)[i-1, 1], B[i, j]=(A^2)[i-1, j])); )); A=B); return(A[n+1, 2])}
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CROSSREFS
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Cf. A102086, A102088.
Sequence in context: A153229 A058006 A013329 this_sequence A052573 A110371 A120388
Adjacent sequences: A102084 A102085 A102086 this_sequence A102088 A102089 A102090
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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), Dec 29 2004
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