%I A104531
%S A104531 1,4,24,148,920,5736,35808,223668,1397496,8732920,54575888,341082504,
%T A104531 2131706864,13322959888,83267756400,520420803060,3252620324280,
%U A104531 20328841669080,127055130786960,794094089779800,4963086293860560
%N A104531 Expansion of (1+sqrt(1-4x))/(5sqrt(1-4x)-3).
%C A104531 Apply the Riordan matrix ((1+sqrt(1-4x))/2,(1-sqrt(1-4x))/2) (inverse 
               of (1/(1-x),x(1-x))) to 5^n.
%F A104531 a(n)=0^n+sum{k=0..n, 4^(k+1)*C(2n-1, n-k-1)2(k+1)/(n+k+1)
%Y A104531 Cf. A088218, A067336, A076025, A104530, A104532.
%Y A104531 Sequence in context: A052609 A077613 A072949 this_sequence A045738 A003288 
               A091166
%Y A104531 Adjacent sequences: A104528 A104529 A104530 this_sequence A104532 A104533 
               A104534
%K A104531 easy,nonn
%O A104531 0,2
%A A104531 Paul Barry (pbarry(AT)wit.ie), Mar 12 2005