A216146 Smallest prime factor of 3*(2n+1)^(2n+1) + 2.

5, 83, 9377, 2470631, 97, 5, 29, 13, 306503, 23173, 5, 7, 7, 11, 12517, 5, 13, 61, 17, 71, 5, 53, 1531477446517, 97, 101, 5, 11, 1999, 53, 11, 5, 67153, 7, 7, 13499, 5, 13, 28201

Offset

0,1

Links

Table of n, a(n) for n=0..37.

Factor DB, 3*(2*n+1)^(2*n+1)+2.

Example

Indices n = 0,1,2,3 correspond to the 4 primes a(n) = 3*(2n+1)^(2n+1) + 2, and to A160360(2,3,4,5) = 1,3,5,7. The next prime is a(46), with 184 digits too large to be displayed here.
a(22)=1531477446517 is the smaller factor of the semiprime 3*45^45+2.

Prog

(PARI) forstep(n=1, 300, 2, forprime(p=1, default(primelimit), Mod(n, p)^n*3+2&next; print1(p", "); next(2)); print1(factor(3*n^n+2)[1, 1]", "))

Crossrefs

Cf. A160360.

Sequence in context: A054953 A215172 A301811 * A111834 A271219 A359110

Adjacent sequences: A216143 A216144 A216145 * A216147 A216148 A216149

Keyword

nonn

Author

M. F. Hasler, Sep 02 2012

Extensions

Comment in example and link added by M. F. Hasler, Feb 03 2014

Status

approved