OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..160
P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G. E. H. Duchamp, Combinatorial field theories via boson normal ordering, arXiv:quant-ph/0405103, 2004-2006. The title of this paper in the arXiv was later changed to "Some useful combinatorial formulas for bosonic operators"
P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G. E. H. Duchamp, Some useful combinatorial formulas for bosonic operators, J. Math. Phys. 46, 052110 (2005) (6 pages).
FORMULA
a(n) = (2n)!*bell(2n)*coeff(exp(x*sinh(x)), x^(2n)). - Emeric Deutsch, Jan 22 2005
MAPLE
with(combinat): a:=n->bell(2*n)*(2*n)!*coeff(series(exp(x*sinh(x)), x=0, 40), x^(2*n)): seq(a(n), n=1..13); # Emeric Deutsch, Jan 22 2005
MATHEMATICA
a[n_] := (2n)! BellB[2n] SeriesCoefficient[Exp[x Sinh[x]], {x, 0, 2n}];
Table[a[n], {n, 1, 11}] (* Jean-François Alcover, Nov 11 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 01 2004
EXTENSIONS
More terms from Emeric Deutsch, Jan 22 2005
STATUS
approved
