A185630 Column 1 of triangle A185628.

1, 3, 12, 55, 315, 2243, 19378, 198363, 2358860, 32060736, 491393909, 8398281337, 158541018923, 3279307650137, 73808041476439, 1796794875356409, 47063878147374980, 1320276655048586177, 39504980013582635300, 1256210676237601811305, 42313074100060933324771

Offset

0,2

Comments

Triangle A185628 equals the matrix cube 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^3)[n+2, 2])}

Crossrefs

Cf. A185620, A185628, A185629, A185631.

Sequence in context: A263533 A064314 A362085 * A284843 A107318 A176281

Adjacent sequences: A185627 A185628 A185629 * A185631 A185632 A185633

Keyword

nonn

Author

Paul D. Hanna, Sep 07 2011

Status

approved