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Convolution of A000085 with itself.
1

%I #11 Nov 05 2019 14:03:45

%S 1,2,5,12,32,88,260,800,2604,8824,31340,115568,443760,1763456,7260256,

%T 30835712,135124496,609027360,2822461648,13417923008,65401203584,

%U 326242088064,1664539966400,8674167861760,46140838036160,250248380068736,1383064482739392,7782094359642880

%N Convolution of A000085 with itself.

%C a(n) is also the moment of order n for the measure of density: x*exp(-(x-1)^2)*erfi((x-1)/sqrt(2)) over the interval -infinity..infinity, with erfi the Imaginary Error Function.

%H Andrew Howroyd, <a href="/A188287/b188287.txt">Table of n, a(n) for n = 0..200</a>

%F a(n) = Sum_{k=0..floor(n/2)} binomial(n+1,2*k+1)*A034430(k).

%o (PARI) seq(n)={Vec(serlaplace(exp(x + x^2/2 + O(x*x^n)))^2)} \\ _Andrew Howroyd_, Nov 04 2019

%Y Cf. A000085, A034430.

%K nonn

%O 0,2

%A _Groux Roland_, Mar 26 2011

%E Terms a(20) and beyond from _Andrew Howroyd_, Nov 04 2019