%I
%S 1,2,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,
%T 2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,
%U 2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4,2,4
%N Expansion of (1+x^2)(1+2x)/(1x^2).
%C Row sums of number triangle A106468.
%F a(0)=1, a(n)=(20^((n1)/2))(1(1)^n)+(20^(n/2))(1+(1)^n)/2, n>1.
%K easy,nonn
%O 0,2
%A _Paul Barry_, May 03 2005
