%I A131765
%S A131765 1,4,36,404,5076,68324,963396,14046964,210062196,3204118724,49656709476,
%T A131765 779690085204,12376867734036,198301332087204,3202580085625476,
%U A131765 52080967814444724,852103170531254196,14016301507253656964
%N A131765 Series reversion of x(1-5x)/(1-x) .
%C A131765 The Hankel transform of this sequence is 20^C(n+1,2) .
%F A131765 a(n) = Sum_{k, 0<=k<=n}A086810(n,k)*4^k .
%F A131765 a(n)=sum{k=0..n, C(n+k,2k)*A000108(k)*(-1)^(n-k)*5^k}; a(n)=sum{k=0..n, 
               C(n+k,2k)*A000108(k)*(4^(k+1)+(-1)^k)/5}. [From Paul Barry (pbarry(AT)wit.ie), 
               Sep 08 2009]
%Y A131765 Sequence in context: A138736 A019999 A002894 this_sequence A132864 A052700 
               A167540
%Y A131765 Adjacent sequences: A131762 A131763 A131764 this_sequence A131766 A131767 
               A131768
%K A131765 nonn
%O A131765 0,2
%A A131765 Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 29 2007
%E A131765 Extra terms added. Paul Barry (pbarry(AT)wit.ie), Sep 08 2009