A104508 Absolute row sums of triangle A104505, which is equal to the right-hand side of the triangle A084610 of coefficients in (1+x-x^2)^n.

1, 2, 4, 9, 20, 47, 103, 198, 512, 1161, 1985, 5590, 13005, 21684, 59294, 142273, 270858, 634187, 1526399, 3256372, 6779657, 16020364, 37758202, 79702477, 164647757, 424655100, 940639154, 1709638551, 4675803604, 10774789429

Offset: 0

Author

Paul D. Hanna, Mar 11 2005

Keywords

• nonn

Crossrefs

Cf. A104505.

Programs

PARI

a(n)=sum(k=0,n,abs(polcoeff((1+x-x^2)^n,n+k)))