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

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