OFFSET
0,2
COMMENTS
Binomial transform of A080954.
a(n) is the permanent of the n X n matrix with 7's on the diagonal and 1's elsewhere.
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..448
FORMULA
a(n) = n!*Sum_{ k = 0..n } 6^k/k!.
a(n) = Sum_{ k = 0..n } A008290(n, k)*7^k.
a(n) Sum_{ k = 0..n } k!*C(n, k)*6^(n-k).
MAPLE
a:=n->n!*sum(6^k/k!, k=0..n): seq(a(n), n=0..20); # Emeric Deutsch, Jul 18 2005
restart:F(x):=exp(6*x)/(1-x): f[0]:=F(x): for n from 1 to 20 do f[n]:=diff(f[n-1], x) od: x:=0: seq(f[n], n=0..18); # Zerinvary Lajos, Apr 03 2009
MATHEMATICA
a[n_] := n! * Sum[6^k/k!, {k, 0, n}]; Array[a, 19, 0] (* Amiram Eldar, Jun 30 2020 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Philippe Deléham, Jul 13 2005
EXTENSIONS
More terms from Emeric Deutsch, Jul 18 2005
STATUS
approved