OFFSET
1,2
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) { s =y ; for(loop=1, 18, p = 1 ; forstep(i= 1, 2*loop-1, 2, sigmai = polcoeff(s, i, y) ; n=0 ; tmp = 0 ; while(i*n <=2*loop-1, ff = 1 ; for(k=1, n, ff *= (-sigmai-k+1)/k ; ) ; tmp += ff*(-y)^(i*n) ; n++ ; ) ; p *= tmp : ) ; print1(polcoeff(p, 2*loop-2, y), ", ") ; b = y-s ; forstep(i=1, 2*loop-1, 2, b += polcoeff(p, i, y)*y^i ; ) ; s = y ; for(r=0, loop-1, for(i=0, 2*loop+1, s += polcoeff(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