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”).

A152456
a(n)=1*(n+2)!-2*(n+1)!-3*n!.
0
-3, -1, 6, 54, 408, 3240, 28080, 267120, 2782080, 31570560, 388281600, 5149267200, 73287244800, 1114636723200, 18045906278400, 309918825216000, 5628230479872000, 107773290713088000, 2170404686241792000
OFFSET
0,1
MATHEMATICA
a[n_]:=1*(n+2)!-2*(n+1)!-3*n!;
CROSSREFS
Sequence in context: A221852 A363196 A025230 * A128605 A051511 A272030
KEYWORD
sign
AUTHOR
EXTENSIONS
Offset changed from 1 to 0 by Georg Fischer, May 08 2021
STATUS
approved