A277554 Positive integers n such that 7^n == 3 (mod n).

1, 2, 46, 2227, 6684830083, 12827743861, 151652531182, 155657642297, 3102126273955, 11006109076099, 50473807426174, 172794904196354

Offset: 1

Author

Max Alekseyev, Oct 19 2016

Keywords

• nonn
• hard
• more

Comments

No other terms below 10^15.

Crossrefs

Cf. A066438, A277126.

Cf. Solutions to 7^n == k (mod n): A277371 (k=-3), A277370 (k=-2), A015954 (k=-1), A067947 (k=1), A277401 (k=2).

Cf. Solutions to b^n == 3 (mod n): A050259 (b=2), A130422 (b=4), A123061 (b=5), A116629 (b=13).

Programs

PARI

isok(n) = Mod(7, n)^n == 3; \\ Michel Marcus, Oct 20 2016