OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
FORMULA
Recurrence: (4*n+3)*a(n) = (4*n^2 + 7*n + 20)*a(n-1) - (4*n^2 + 16*n - 11)*a(n-2) + 9*(n-2)*a(n-3). - Vaclav Kotesovec, Oct 17 2012
a(n) ~ 4*e*n!. - Vaclav Kotesovec, Oct 17 2012
MATHEMATICA
CoefficientList[Series[E^x*(x^2+x+2)/(1-x), {x, 0, 20}], x]* Table[n!, {n, 0, 20}] (* Vaclav Kotesovec, Oct 17 2012 *)
PROG
(PARI) x='x+O('x^66); Vec(serlaplace(exp(x)*(x^2+x+2)/(1-x))) \\ Joerg Arndt, May 15 2013
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Creighton Dement, May 19 2005
STATUS
approved