OFFSET
0,3
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
R. C. Read, On the enumeration of a class of plane multigraphs, Aequat. Math. 31 (1986) no 1, 47-63.
PROG
(PARI) { my(s =y); for(loop=1, 18, my(p = 1); forstep(i= 1, 2*loop-1, 2, my(sigmai = polcoef(s, i, y)) ; if(i==2*loop-1, print1(sigmai, ", "); ) ; my(n=0, tmp = 0); while(i*n <=2*loop-1, my(ff = 1); for(k=1, n, ff *= (-sigmai-k+1)/k ; ) ; tmp += ff*(-y)^(i*n) ; n++ ; ) ; p *= tmp ; ) ; my(b = y-s); forstep(i=1, 2*loop-1, 2, b += polcoef(p, i, y)*y^i ; ) ; s = y ; for(r=0, loop-1, for(i=0, 2*loop+1, s += polcoef(b^(3+2*r), i, y)*y^i ; ) ; ) ; ) ; } \\ R. J. Mathar, Apr 24 2006
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from R. J. Mathar, Apr 24 2006
More terms from Sean A. Irvine, Nov 07 2017
STATUS
approved