A047768 a(n) = A047766(6n+2).

0, 0, 1, 5, 26, 133, 708, 3861, 21604, 123266, 715221, 4206956, 25032840, 150413348, 911379384, 5562367173, 34164355848, 211015212580, 1309815397995, 8166460799805, 51120054233490, 321156223592865, 2024257417812240, 12797201858645100

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Comments

Is this the same as A047755? - R. J. Mathar, Oct 18 2008