login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A293117
E.g.f.: exp(x^2/(x-1)).
3
1, 0, -2, -6, -12, 0, 240, 2520, 21840, 181440, 1481760, 11642400, 80498880, 311351040, -4739454720, -183437654400, -4300276780800, -88851284121600, -1754954007206400, -34107089784768000, -659574028252339200, -12724865943229440000, -244046146272658329600
OFFSET
0,3
LINKS
FORMULA
D-finite with recurrence a(n) = (2*n-2)*a(n-1) - (n^2-n)*a(n-2) + (n^2-3*n+2)*a(n-3). - Robert Israel, Apr 29 2021
MAPLE
a:= proc(n) option remember; `if`(n=0, 1, -add(
a(n-j)*binomial(n-1, j-1)*j!, j=2..n))
end:
seq(a(n), n=0..25); # Alois P. Heinz, Sep 30 2017
MATHEMATICA
CoefficientList[Series[E^(-x^2/(1-x)), {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Sep 30 2017 *)
PROG
(PARI) x='x+O('x^66); Vec(serlaplace(exp(x^2/(x-1))))
CROSSREFS
Column k=1 of A293119.
Cf. A052845.
Sequence in context: A342540 A328449 A293589 * A293122 A014452 A188894
KEYWORD
sign
AUTHOR
Seiichi Manyama, Sep 30 2017
STATUS
approved