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A006091
a(n) = n^n - n + 1.
(Formerly M3111)
5
1, 3, 25, 253, 3121, 46651, 823537, 16777209, 387420481, 9999999991, 285311670601, 8916100448245, 302875106592241, 11112006825558003, 437893890380859361, 18446744073709551601, 827240261886336764161, 39346408075296537575407, 1978419655660313589123961
OFFSET
1,2
COMMENTS
Related to famous "coconuts" problem - cf. A002021, A002022.
Also main diagonal of A193871. - Omar E. Pol, Aug 22 2011
REFERENCES
Archimedeans Problems Drive, Eureka, 41 (1981), 7.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Archimedeans Problems Drive, Problems for 1980, Eureka, 41 (1981), 6-7. (Annotated scanned copy)
FORMULA
E.g.f.: 1/(1 + LambertW(-x)) + exp(x)*(1 - x) - 2. - Ilya Gutkovskiy, Oct 30 2017
MATHEMATICA
Table[n^n-n+1, {n, 20}] (* Harvey P. Dale, Jun 09 2011 *)
PROG
(Magma) [n^n - n + 1: n in [1..20]]; // Vincenzo Librandi, Aug 23 2011
(PARI) A006091(n)=n^n-n+1 \\ M. F. Hasler, Oct 30 2017
CROSSREFS
Cf. A014293.
Sequence in context: A260209 A086655 A064326 * A357232 A355865 A009042
KEYWORD
nonn,easy
STATUS
approved