A174881 -id:A174881 - cp's OEIS frontend

A176245 Primes of the form A174881(k)+1.

3, 37, 160001

Offset: 1

Jonathan Vos Post, Apr 12 2010

There are no primes of the form A174881(k)-1.
There are no further terms through ((40*(40+1))^40) + 1 = 52330005981567385600000001 * 7498996269037701079813541255115132352481561590213553612395236504891175431182405289081378432614400.
Contribution from Farideh Firoozbakht, Apr 22 2010: (Start)
Each term is of the form (4^n+2^n)^2^n+1. Next term (if it exists) is
greater than (4^15+2^15)^2^15, so it has more than 295924 digits. (End)

			a(1) = (1^1)*((1+1)^1) + 1 = 2 + 1 = 3 is prime.
a(2) = (2^2)*((2+1)^2) + 1 = 36 + 1 = 37 is prime.
a(3) = (4^4)*((4+1)^4) + 1 = 160000 + 1 = 160001 is prime.

Cf. A000040, A000169, A000312, A174881.

Edited by Farideh Firoozbakht and N. J. A. Sloane, Apr 18 2010

A281997 a(n) = (n-1)^n * n^n.

Original entry on oeis.org

0, 4, 216, 20736, 3200000, 729000000, 230539333248, 96717311574016, 51998697814228992, 34867844010000000000, 28531167061100000000000, 27982542656501458535448576, 32405578483833249047003529216, 43752153272681450786889799450624

Offset: 1

Daniel Suteu, Feb 04 2017

Cf. A000312, A007778, A174881.

Table[(n (n - 1))^n, {n, 14}] (* Michael De Vlieger, Feb 05 2017 *)

PARI
```
a(n) = (n*(n-1))^n;
```

a(n) ~ A174881(n) / e^2.

a(n) = A007778(n-1)*A000312(n). - Felix Fröhlich, Feb 05 2017

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A176245 Primes of the form A174881(k)+1.

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A281997 a(n) = (n-1)^n * n^n.

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