cp's OEIS Frontend

A132831 Largest terms a(n) forming a self-convolution of an integer sequence (A132832) such that: a(n) <= 2*a(n-1) for n>0 with a(0)=1.

%I A132831 #2 Mar 30 2012 18:37:04
%S A132831 1,2,3,6,11,22,44,88,175,350,700,1400,2799,5598,11195,22390,44779,
%T A132831 89558,179115,358230,716459,1432918,2865835,5731670,11463340,22926680,
%U A132831 45853360,91706720,183413439,366826878,733653755,1467307510,2934615019
%N A132831 Largest terms a(n) forming a self-convolution of an integer sequence (A132832) such that: a(n) <= 2*a(n-1) for n>0 with a(0)=1.
%C A132831 a(n) ~ 2^n*c where c=0.683268303731665578137197731736227240453607...
%o A132831 (PARI) {a(n)=local(B=[1],t);if(n==0,1,for(k=1,n,t=2*a(k-1);B=concat(B,t); B[ #B]=t+1-denominator(Vec(Ser(B)^(1/2))[ #B]) ));B[n+1]}
%Y A132831 Cf. A132832.
%K A132831 nonn
%O A132831 0,2
%A A132831 _Paul D. Hanna_, Sep 07 2007