OFFSET
1,2
LINKS
Gheorghe Coserea, Table of n, a(n) for n = 1..210
PROG
(PARI)
A286781_ser(N, t='t) = {
my(x='x+O('x^N), y0=1+O('x^N), y1=0, n=1);
while(n++,
y1 = (1 + x*y0 + 2*x^2*y0')*(1 - x*y0*(1-t))/(1-x*y0)^2;
if (y1 == y0, break()); y0 = y1; );
y0;
};
Kol(K, N=20) = {
my(s = A286781_ser(N+K, 't+O('t^(K+1))));
vector(N, n, polcoeff(polcoeff(s, K+n-1), K));
};
Kol(1)
CROSSREFS
KEYWORD
nonn
AUTHOR
Gheorghe Coserea, May 16 2017
STATUS
approved