A211231 Row sums of A211230.

1, 3, 6, 10, 27, 33, 108, 108, 405, 351, 1458, 1134, 5103, 3645, 17496, 11664, 59049, 37179, 196830, 118098, 649539, 373977, 2125764, 1180980, 6908733, 3720087, 22320522, 11691702, 71744535

Offset: 0

Author

Peter Bala, Apr 05 2012

Keywords

• nonn
• easy

Crossrefs

Cf. A211227, A211230.

Formula

a(2*n) = (n+1)*3^n; a(2*n+1) = (n+9)*3^(n-1).

O.g.f.: (1+3*x-8*x^3)/(1-3*x^2)^2 = 1 + 3*x + 6*x^2 + 10*x^3 + ....