OFFSET
0,3
LINKS
W. G. Brown, Enumeration of non-separable planar maps, Canad. J. Math., 15 (1963), 526-545.
W. G. Brown, Enumeration of non-separable planar maps
MAPLE
T := proc(n, k) if k<=n then k*sum((2*j-k)*(j-1)!*(3*n-j-k-1)!/(j-k)!/(j-k)!/(2*k-j)!/(n-j)!, j=k..min(n, 2*k))/(2*n-k)! else 0 fi end: seq(seq(T(n, n-k+1), k=1..n), n=1..11); # Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 19 2008
MATHEMATICA
t[n_, k_] := If[k <= n, k*Sum[(2*j-k)*(j-1)!*(3*n-j-k-1)!/(j-k)!/(j-k)!/(2*k-j)!/(n-j)!, {j, k, Min[n, 2*k]}]/(2*n-k)!, 0]; Table[Table[t[n, n-k+1], {k, 1, n}], {n, 1, 11}] // Flatten (* Jean-François Alcover, Jan 14 2014, after Herman Jamke *)
CROSSREFS
KEYWORD
AUTHOR
EXTENSIONS
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 19 2008
STATUS
approved