A121413 Column 1 of triangle A121412, in which row n of T equals row (n-1) of T^(n+1) with an appended '1'.

1, 1, 4, 30, 335, 4984, 92652, 2065146, 53636520, 1589752230, 52926799310, 1954793723688, 79297921097850, 3504206787532290, 167533486104374420, 8615231103973721610, 474145710046504872894, 27806642356199323970739

Offset

0,3

Comments

Also equals column 3 of triangle A101479.

Links

Table of n, a(n) for n=0..17.

Prog

(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+2, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^1)[n+2, 2])}

Crossrefs

Cf. A121412 (triangle); other columns: A101483, A121414, A121415; A101479 (triangle).

Sequence in context: A277759 A006149 A207833 * A001761 A292220 A099712

Adjacent sequences: A121410 A121411 A121412 * A121414 A121415 A121416

Keyword

nonn

Author

Paul D. Hanna, Aug 22 2006

Status

approved