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A155159
a(n) = 1 + 2*n*n!.
1
1, 3, 9, 37, 193, 1201, 8641, 70561, 645121, 6531841, 72576001, 878169601, 11496038401, 161902540801, 2440992153601, 39230231040001, 669529276416001, 12093372555264001, 230485453406208001, 4622513815535616001
OFFSET
0,2
LINKS
FORMULA
From G. C. Greubel, Mar 20 2021: (Start)
a(n) = 2*A001563(n) + 1.
E.g.f.: exp(x) + 2*x/(1-x)^2. (End)
MAPLE
A155159:= 2*((n+1)! - n!) + 1; seq(A155159(n), n=0..30); # G. C. Greubel, Mar 20 2021
MATHEMATICA
Table[1 + 2*n*n!, {n, 0, 30}]
PROG
(Magma) [1 + 2*n*Factorial(n): n in [0..30]]; // G. C. Greubel, Mar 20 2021
(Sage) [1 + 2*n*factorial(n) for n in (0..30)] # G. C. Greubel, Mar 20 2021
CROSSREFS
Cf. A001563.
Sequence in context: A030943 A030803 A300170 * A222518 A107886 A220452
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Jan 21 2009
STATUS
approved