OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..449
Michael Engen and Vincent Vatter, Containing all permutations, Amer. Math. Monthly, 128 (2021), 4-24; arXiv preprint, arXiv:1810.08252 [math.CO], 2018-2020.
FORMULA
E.g.f.: (1/(1 - x) - exp(x)) * (2 - x) - log(1 - x). - Ilya Gutkovskiy, Feb 15 2021
MATHEMATICA
Array[#2 + (#1 + 1) #2 + #1 - 1 & @@ {#, #!} &, 22, 0] (* Michael De Vlieger, Apr 07 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 13 2021
STATUS
approved