A274509 a(n) is the only number m such that 5^(2^m) + 1 is divisible by A273946(n).

0, 1, 3, 7, 2, 5, 6, 4, 3, 9, 15, 13, 17, 11, 8, 19, 18, 11, 9, 4, 16, 5, 23, 24, 17, 19, 17, 5, 36, 6, 32, 23, 34, 40, 41, 39, 25

Offset

1,3

Links

Table of n, a(n) for n=1..37.

Prog

(PARI) forstep(p=3, 10^15, 2, if(!Mod(p, 5)==0, if(isprime(p), o=znorder(Mod(5, p)); x=ispower(2*o); if(2^(x-1)==o, print1(x-2, ", ")))));

Crossrefs

Cf. A273946.

Sequence in context: A336893 A226521 A091723 * A016618 A130789 A023529

Adjacent sequences: A274506 A274507 A274508 * A274510 A274511 A274512

Keyword

nonn,more

Author

Arkadiusz Wesolowski, Jun 25 2016

Status

approved