|
%I #13 Oct 24 2017 09:30:24
%S 1,9,99,1233,16929,251829,4012011,67876461,1211592897,22700600001,
%T 444567396051,9068604811209,192115381719969,4216003141209453,
%U 95631348748295259,2237799925576748709,53928909429116324481,1336410276724468307961
%N E.g.f.: exp(3*((1+x)^3 - 1)).
%H Seiichi Manyama, <a href="/A294120/b294120.txt">Table of n, a(n) for n = 0..511</a>
%F a(n) ~ 3^(2*n/3 - 1/2) * n^(2*n/3) * exp(-2 + 3^(1/3)*n^(1/3) + 3^(2/3)*n^(2/3) - 2*n/3). - _Vaclav Kotesovec_, Oct 23 2017
%t nmax = 20; CoefficientList[Series[E^(3*((1+x)^3 - 1)), {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 23 2017 *)
%o (PARI) N=66; x='x+O('x^N); Vec(serlaplace(exp(3*((1+x)^3-1))))
%Y Column k=3 of A294118.
%K nonn
%O 0,2
%A _Seiichi Manyama_, Oct 23 2017
|
