A245241 Integers n such that 6 * 7^n + 1 is prime.

0, 1, 4, 9, 99, 412, 2633, 5093, 5632, 28233, 36780, 47084, 53572

Offset

1,3

Comments

All terms correspond to verified primes, that is, not merely probable primes.

a(14) > 2*10^5.

Links

Table of n, a(n) for n=1..13.

Example

4 is in this sequence because 6 * 7^4 + 1 = 14407, which is prime.

Mathematica

Select[Range[0, 200000], PrimeQ[6 * 7^# + 1] &]

Crossrefs

Cf. A003307, A002235, A046865, A079906, A001771, A005541, A056725, A046867, A079907.

Cf. A005537, A005538, A005539, A216889, A216890, A247260.

Sequence in context: A220972 A335088 A247009 * A115690 A115689 A061457

Adjacent sequences: A245238 A245239 A245240 * A245242 A245243 A245244

Keyword

nonn,more

Author

Robert Price, Nov 14 2014

Status

approved