OFFSET
0,3
FORMULA
a(n) ~ 3^(n-1/2)*sqrt(2)*n^(n-1)/exp(n-1). - Vaclav Kotesovec, Jun 02 2013
Conjecture D-finite with recurrence: a(n) +(-2*n+3)*a(n-1) +(-3*n^2+12*n-10)*a(n-2) +3*(-2*n+3)*a(n-3) -9*(n-1)*(n-3)*a(n-4)=0. - R. J. Mathar, Jan 24 2020
MATHEMATICA
With[{nn=20}, CoefficientList[Series[Exp[1-Sqrt[1-2x-3x^2]], {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Mar 26 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 07 2009
STATUS
approved