A078179 -id:A078179 - cp's OEIS frontend

A076846 Primes of the form n^k + n - 1, where k>0 is minimal.

3, 5, 7, 29, 11, 13, 71, 17, 19, 131, 23, 181, 2177953337809371149, 29, 31, 83537, 5849, 37, 419, 41, 43, 279863, 47, 15649, 701, 53, 811, 420707233300229, 59, 61

Offset: 2

Benoit Cloitre, Nov 20 2002

nonn

The next term is too large to include.

Reinhard Zumkeller, Table of n, a(n) for n = 2..100

Cf. A076845, A078179, A010051, A002327.

a076846 n = n ^ (a076845 n) + n - 1
-- Reinhard Zumkeller, Jul 17 2014

Offset corrected by Reinhard Zumkeller, Jul 17 2014

A078178 Least k>=2 such that n^k + n - 1 is prime.

Original entry on oeis.org

2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 4, 2, 16, 2, 2, 4, 3, 2, 2, 2, 7, 4, 2, 3, 2, 3, 2, 10, 2, 2, 108, 3, 6, 2, 3, 7, 2, 2, 4, 2, 16, 3, 2, 2, 2, 20, 2, 7, 2, 3, 3, 2, 2, 2, 2, 9, 4, 2, 2, 7, 8, 3, 2, 2, 2, 24, 2, 6, 2, 12, 4, 3, 8, 6, 2, 4, 3, 9, 194, 3, 13, 2, 8, 2, 2, 3, 8, 2, 10, 6, 4, 2, 2, 54, 2, 132, 4, 10, 2

Offset: 2

Reinhard Zumkeller, Nov 20 2002

nonn

n^a(n) + n - 1 = A078179(n).

			7^2+7-1=5*11, but 7^3+7-1=349=A000040(70), therefore a(7)=3.

Cf. A076845, A078179.

Cf. A010051.

a078178 n = head [k | k <- [2..], a010051'' (n ^ k + n - 1) == 1]
-- Reinhard Zumkeller, Jul 16 2014

lkp[n_]:=Module[{k=2},While[!PrimeQ[n^k+n-1],k++];k]; Array[lkp,100,2] (* Harvey P. Dale, May 24 2020 *)

More terms from Benoit Cloitre, Nov 20 2002

cp's OEIS Frontend

A076846 Primes of the form n^k + n - 1, where k>0 is minimal.

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