A185625 Column 0 of triangle A185624; also, equals row sums of triangle A185620.

1, 2, 3, 6, 18, 79, 463, 3396, 30073, 314037, 3796561, 52332869, 812013163, 14029926801, 267461387125, 5581705418715, 126657160962835, 3106644875467396, 81943115662983569, 2313753122033185373, 69654973411269008826, 2227679407193350385775

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..21.

Prog

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

Crossrefs

Cf. A185620, A185624, A185626, A185627, A185628.

Sequence in context: A038056 A072241 A093468 * A114302 A000304 A000614

Adjacent sequences: A185622 A185623 A185624 * A185626 A185627 A185628

Keyword

nonn

Author

Paul D. Hanna, Sep 07 2011

Status

approved