A104508 - OEIS

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.

%I #4 Mar 30 2012 18:36:45

%S 1,2,4,9,20,47,103,198,512,1161,1985,5590,13005,21684,59294,142273,

%T 270858,634187,1526399,3256372,6779657,16020364,37758202,79702477,

%U 164647757,424655100,940639154,1709638551,4675803604,10774789429

%N 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.

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

%Y Cf. A104505.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Mar 11 2005