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A124923 n^(n-1) + 1. 4
2, 3, 10, 65, 626, 7777, 117650, 2097153, 43046722, 1000000001, 25937424602, 743008370689, 23298085122482, 793714773254145, 29192926025390626, 1152921504606846977, 48661191875666868482, 2185911559738696531969 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Prime p divides a(p-1). n divides a(n-1) for all prime n and all odd composite n. p divides a((p+1)/2) for prime p = {3,5,11,13,19,29,37,43,53,59,61,67,83,...} = A003629(n) = Primes congruent to {3,5} mod 8. p divides a((p+3)/4) for prime p = {13,73,97,109,181,229,241,277,337,409,421,457,541,709,733,757,829,...} = A107141(n) Primes of the form 4x^2+9y^2. p divides a((p+5)/6) for prime p = {43,61,79,109,151,163,181,193,313,337,433,523,577,631,643,673,787,829,907,991,...}. p divides a((p+7)/8) for prime p = {113,137,569,641,673,1129,1289,1297,1481,1801,...}. p divides a((3p-1)/2) for prime p = {5,7,13,23,29,31,37,47,53,61,71,79,101,103,109,127,149,151,157,167,173,181,191, 197,199,...} = A003628(n) Primes congruent to {5, 7} mod 8. p^2 divides a((3p-1)/2) for prime p = {5,13,173,5501,...} = A124924(n)..

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..200

FORMULA

a(n) = n^(n-1) + 1. a(n) = A000169(n) + 1.

MATHEMATICA

Table[n^(n-1)+1, {n, 1, 30}]

PROG

(MAGMA) [n^(n-1) + 1: n in [1..20]]; // Vincenzo Librandi, Aug 14 2012

CROSSREFS

Cf. A000169, A003629, A107141, A003628, A124924.

Sequence in context: A173097 A088221 A206296 * A291935 A088222 A184249

Adjacent sequences:  A124920 A124921 A124922 * A124924 A124925 A124926

KEYWORD

nonn,easy

AUTHOR

Alexander Adamchuk, Nov 12 2006

STATUS

approved

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Last modified October 22 14:46 EDT 2018. Contains 316487 sequences. (Running on oeis4.)