A047139 T(2n,n), array T as in A047130.

1, 2, 9, 48, 261, 1534, 9319, 56808, 353362, 2227380, 14099553, 89931668, 577292621, 3718701300, 24047442913, 156059054586, 1015345651345, 6621929417524, 43283675452318, 283439130488986, 1859169844171611

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Crossrefs

Sequence in context: A323958 A306356 A188818 * A190315 A190253 A174687

Adjacent sequences: A047136 A047137 A047138 * A047140 A047141 A047142

Keyword

nonn

Author

Definition revised by Clark Kimberling, Dec 08 2006

Status

approved