A192470 (A192469)/2.

1, 4, 22, 112, 589, 3100, 16393, 86800, 459994, 2438536, 12929377, 68557720, 363537265, 1927735708, 10222301758, 54206461120, 287444443765, 1524252798580, 8082769233721, 42861108613288, 227282835266626, 1205229864917272

Offset: 1

Author

Clark Kimberling, Jul 01 2011

Keywords

• nonn

Comments

See A192469.

Crossrefs

Cf. A192469.

Programs

Mathematica

(See A192468.)

Formula

Empirical G.f.: -x*(x-1)*(3*x-1)/((3*x^2+x-1)*(9*x^2-7*x+1)). [Colin Barker, Nov 12 2012]