A287041 - OEIS

%I #8 May 20 2017 21:55:19

%S 5,77,1044,14784,227877,3862305,71983440,1469813400,32718512925,

%T 789901955325,20578796752500,575836554270600,17232413940017325,

%U 549370878062313825,18591830334684129600,665771181527890746000,25154357611638416671125,1000094581801108086418125,41741166856778766269392500

%N Column 1 of A286783.

%H Gheorghe Coserea, <a href="/A287041/b287041.txt">Table of n, a(n) for n = 2..211</a>

%o (PARI)

%o A286781_ser(N, t='t) = {

%o   my(x='x+O('x^N), y0=1+O('x^N), y1=0, n=1);

%o   while(n++,

%o     y1 = (1 + x*y0 + 2*x^2*y0')*(1 - x*y0*(1-t))/(1-x*y0)^2;

%o     if (y1 == y0, break()); y0 = y1;);

%o   y0;

%o };

%o Kol(K, N=20) = {

%o   my(s = A286781_ser(N+K+1, 't+O('t^(K+1))),

%o      p = (1 + x*s + 2*x^2*s')/(1-x*s)^2);

%o   vector(N, n, polcoeff(polcoeff(p, K+n), K));

%o };

%o Kol(1)

%Y Cf. A286783.

%K nonn

%O 2,1

%A _Gheorghe Coserea_, May 19 2017