A104448 Row sums of triangle A104446.

1, 3, 6, 13, 33, 101, 372, 1624, 8263, 48285, 320031, 2380114, 19675986, 179314868, 1788473424, 19398149629, 227510745445, 2871040422932, 38810001746171, 559745948482030, 8582882169611759, 139467832061599433

Offset

0,2

Comments

A104446 equals the square of triangular matrix A104445, read by rows, where X=[A104445] satisfies: SHIFT_LEFT_UP(X) = X^2 - X + I.

Links

Table of n, a(n) for n=0..21.

Formula

a(n) = A091352(n) + A091352(n-1) for n>0.

Prog

(PARI) a(n)=local(A=Mat(1), B); for(m=1, n+1, B=A^2-A+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(sum(k=1, n+1, (A^2)[n+1, k]))

Crossrefs

Cf. A104446, A104445, A091352, A091351.

Sequence in context: A358454 A361932 A201951 * A352864 A062466 A366940

Adjacent sequences: A104445 A104446 A104447 * A104449 A104450 A104451

Keyword

nonn

Author

Paul D. Hanna, Mar 08 2005

Status

approved