A107957 Partial sums of A107947.
1, 3, 6, 11, 17, 25, 36, 52, 69, 88, 110, 137, 170, 211, 263, 331, 400, 471, 545, 624, 709, 802, 906, 1026, 1163, 1319, 1497, 1702, 1940, 2219, 2550, 2949, 3349, 3751, 4156, 4566, 4982, 5406, 5841, 6292, 6760, 7247, 7756, 8292, 8861, 9471, 10133, 10863
Offset: 0
Keywords
Examples
a(3) = 6 = 22 - 16 = A107947(2^3 + 3) - A107947(2^3). a(5) = 17 = 85 - 68 = A107947(2^4 + 5) - A107947(2^4). a(8) = 52 = 120 - 68 = A107947(2^4 + 8) - A107947(2^4).
Programs
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PARI
{a(n)=local(A=[1,2]);for(i=1,#binary(n), B=vector(#A,k,polcoeff(Ser(A)/(1-x),k-1)+A[2^#binary(#A-1)]); A=concat(A,B););sum(k=1,n,A[k])}
Comments