A156710 Triangle read by rows, A123191 * (A002605 * (A002605 * 0^(n-k))).

1, 1, 1, 1, 3, 1, 1, 3, 6, 6, 1, 3, 6, 18, 16, 1, 3, 6, 18, 48, 44, 1, 3, 6, 18, 48, 132, 120, 136, 18, 48, 132, 360, 328, 1, 3, 6, 18, 48, 132, 360, 984, 896, 1, 3, 6, 18, 48, 132, 360, 984, 2688, 2448, 1, 3, 6, 18, 48, 132, 360, 984, 2688, 7344, 6688

Offset

0,5

Comments

Row sums = A002605: (1, 2, 6, 16, 44, 120,...)

As a property of eigentriangles, sum of row terms = rightmost term of next row.

Links

Table of n, a(n) for n=0..63.

Formula

Triangle read by rows, A123191 * (A002605 * (A002605 * 0^(n-k))). A123191 is

unsigned, (A002605 * 0^(n-k))= an infinite lower triangular matrix with

A002605 as the main diagonal prefaced with a 1: (1, 1, 2, 6, 16, 44,...)

and the rest zeros.

Example

First few rows of the triangle =
1;
1, 1;
1, 3, 2;
1, 3, 6, 6;
1, 3, 6, 18, 16;
1, 3, 6, 18, 48, 44;
1, 3, 6, 18, 48, 132, 120;
1, 3, 6, 18, 48, 132, 360, 328;
1, 3, 6, 18, 48, 132, 360, 984, 896;
1, 3, 6, 18, 48, 132, 360, 984, 2688, 2448;
1, 3, 6, 18, 48, 132, 360, 984, 2688, 7344, 6688;
...

Crossrefs

Cf. A002605, A123191.

Sequence in context: A308624 A133825 A365968 * A114588 A253223 A121745

Adjacent sequences: A156707 A156708 A156709 * A156711 A156712 A156713

Keyword

nonn,tabl

Author

Gary W. Adamson, Feb 14 2009

Status

approved