A128323 Column 2 of triangle A128320.

1, 5, 12, 73, 418, 3110, 23920, 207549, 1885166, 18417710, 187881112, 2018628090, 22533601892, 261966343388, 3149344100224, 39158513865053, 501507474201750, 6611648592425790, 89492095211184360, 1242626064512513070

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Prog

(PARI)

Crossrefs

Cf. A128320 (triangle), A128321 (column 0), A128322 (column 1), A128324 (row sums); variant: A115083.

Sequence in context: A156236 A209481 A209340 * A202203 A074245 A235939

Adjacent sequences: A128320 A128321 A128322 * A128324 A128325 A128326

Keyword

nonn

Author

Paul D. Hanna, Feb 25 2007

Status

approved