A172403 G.f.: 1/(1-x) = Sum_{n>=0} a(n)*x^n/(1+x)^(2^(n+2)-4).
1, 1, 5, 51, 1059, 44620, 3795202, 649054326, 222639357434, 152968659433948, 210361428050679489, 578800452225641673965, 3185715127946958245708501, 35071788327149162320178667272, 772254422082165524711277630023576
Offset: 0
Keywords
Examples
1/(1-x) = 1 + x/(1+x)^4 + 5*x^2/(1+x)^12 + 51*x^3/(1+x)^28 + 1059*x^4/(1+x)^60 +...
Programs
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PARI
{a(n)=if(n==0,1,polcoeff(-(1-x)*sum(m=0,n-1,a(m)*x^m/(1+x +x*O(x^n))^(2^(m+2)-4)),n))}
Formula
Column 2 of triangle A172400.