A185629 Column 0 of triangle A185628; also, equals row sums of triangle A185624.

1, 3, 6, 16, 60, 305, 1988, 15951, 153171, 1722693, 22296396, 327270440, 5381716953, 98134088419, 1967105567802, 43024511648982, 1020235144731236, 26083065249549660, 715430961891290714, 20962974995245684878, 653654392800091507791, 21615444263990028093227

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..21.

Prog

(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+1, 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+1, 1])}

Crossrefs

Cf. A185620, A185628, A185630, A185631.

Sequence in context: A367639 A340498 A288850 * A107885 A051271 A028405

Adjacent sequences: A185626 A185627 A185628 * A185630 A185631 A185632

Keyword

nonn

Author

Paul D. Hanna, Sep 07 2011

Status

approved