A185627 - OEIS

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A185627

Column 2 of triangle A185624.

1, 2, 11, 66, 470, 3997, 40079, 466448, 6208551, 93297013, 1565360082, 29047075343, 591275224311, 13110484254998, 314726620750589, 8135993235767295, 225426087495479680, 6666553071325468948, 209645759506867904384, 6987310422457948266944, 246075579251657940919613

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OFFSET

0,2

COMMENTS

Triangle A185624 equals the matrix square of triangle R = A185620, which satisfies: R^3 - R^2 + I = R shifted left one column.

LINKS

Table of n, a(n) for n=0..20.

PROG

(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+2, B=A^3-A^2+A^0; A=matrix(m+1, m+1); for(i=1, m+1, for(j=1, i, if(i<2|j==i, A[i, j]=1, if(j==1, A[i, j]=1, A[i, j]=B[i-1, j-1]))))); return((A^2)[n+3, 3])}

CROSSREFS

Cf. A185620, A185624, A185625, A185626, A185628.

Sequence in context: A143816 A220783 A160852 * A216585 A245277 A138792

Adjacent sequences: A185624 A185625 A185626 * A185628 A185629 A185630

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Sep 07 2011

STATUS

approved