A102087 - OEIS

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A102087

Column 1 of triangular matrix A102086, which shifts upward to exclude the main diagonal under matrix square.

0, 2, 4, 20, 156, 1664, 22684, 378572, 7504640, 172785512, 4540756252, 134330010172, 4423176368332, 160596613105384, 6378859853838480, 275308217428662672, 12836003750434047344, 643227594173121801096 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	PROG	`(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])}`
	CROSSREFS	`Cf. A102086, A102088.` `Sequence in context: A058006 A153229 A013329 * A052573 A110371 A120388` `Adjacent sequences: A102084 A102085 A102086 * A102088 A102089 A102090`
	KEYWORD	`nonn`
	AUTHOR	`Paul D. Hanna (pauldhanna(AT)juno.com), Dec 29 2004`

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Last modified February 14 23:44 EST 2012. Contains 205689 sequences.