OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..445
M. Janjic and B. Petkovic, A Counting Function, arXiv 1301.4550 [math.CO], 2013
FORMULA
E.g.f.: -(2-4*x + 3*x^2)/(-6*x^2 - 2 + 6*x + 2*x^3).
a(n) = (4 - n + n^2)*n!/4. - G. C. Greubel, May 04 2018
MAPLE
seq(1/4*(4-n+n^2)*n!, n=0..30);
MATHEMATICA
Table[(4 -n +n^2)*n!/4, {n, 0, 30}] (* G. C. Greubel, May 04 2018 *)
PROG
(PARI) for(n=0, 30, print1((4 -n +n^2)*n!/4, ", ")) \\ G. C. Greubel, May 04 2018
(Magma) [(4 -n +n^2)*Factorial(n)/4: n in [0..30]]; // G. C. Greubel, May 04 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Detlef Pauly (dettodet(AT)yahoo.de), Mar 14 2003
STATUS
approved