%I A122877
%S A122877 0,1,2,7,20,65,206,679,2248,7569,25690,88055,303964,1056497,3693158,
%T A122877 12977655,45813008,162400609,577843890,2063053991,7388487460,
%U A122877 26535797729,95552015614,344897769991,1247685613272
%N A122877 Expansion of (1-2x-3x^2-(1-x)*sqrt(1-2x-7x^2))/(8x^3).
%C A122877 Binomial transform is A071357.
%F A122877 a(n)=sum{k=0..n, C(n,k)*2^((k-1)/2)C((k-1)/2+1)(1-(-1)^k)/2}, where C(n)=A000108(n); 
               a(n)=(1/pi)*Int(x^n*sqrt(-x^2+2x+7)(x-1)/8,x,1-2sqrt(2),1+2sqrt(2));
%Y A122877 Sequence in context: A000935 A035071 A055891 this_sequence A000150 A115117 
               A029890
%Y A122877 Adjacent sequences: A122874 A122875 A122876 this_sequence A122878 A122879 
               A122880
%K A122877 easy,nonn
%O A122877 0,3
%A A122877 Paul Barry (pbarry(AT)wit.ie), Sep 16 2006