A297966 a(n) = 3^n mod prime(n).

1, 0, 2, 4, 1, 1, 11, 6, 18, 5, 13, 10, 38, 36, 42, 15, 19, 34, 5, 32, 46, 51, 49, 39, 94, 30, 73, 53, 9, 91, 114, 100, 79, 121, 38, 127, 122, 113, 126, 138, 82, 114, 118, 112, 119, 10, 108, 30, 188, 20, 188, 30, 174, 169, 5, 52, 15, 241, 202, 222, 50, 267

Offset: 1

Author

Vincenzo Librandi, Jan 11 2018

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A000040, A000244, A064367, A066601.

Programs

GAP

P:=Filtered([1..1500],IsPrime);;List([1..65],n->PowerModInt(3,n,P[n])); # Muniru A Asiru, Mar 12 2018

Magma

[Modexp(3, n, NthPrime(n)): n in [1..80]];

Maple

seq(3 &^ n mod ithprime(n), n=1..65); # Muniru A Asiru, Mar 12 2018

Mathematica

Array[PowerMod[3, #, Prime@#]&, 80]

PARI

a(n) = lift(Mod(3, prime(n))^n); \\ Michel Marcus, Jan 11 2018

Formula

a(n) = A000244(n) mod A000040(n).