A174620 - OEIS

A174620

a(n) = 2^A141468(n) mod prime(n), where A141468(n) is the n-th nonnegative nonprime.

1, 2, 1, 1, 3, 5, 4, 11, 8, 27, 2, 36, 1, 42, 24, 13, 11, 19, 45, 5, 8, 50, 71, 2, 86, 78, 15, 74, 16, 112, 4, 68, 14, 106, 66, 32, 79, 26, 25, 18, 76, 6, 78, 150, 163, 63, 69, 98, 189, 17, 184, 40, 1, 125, 249, 187, 229, 69, 169, 81, 264, 172, 18, 209, 114, 277, 1, 128, 46, 21

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Paolo Xausa, Table of n, a(n) for n = 1..10000

EXAMPLE

a(14) = 12 because (2^A141468(14) mod prime(14)) = (2097152 mod 43) = 12.

MATHEMATICA

MapIndexed[PowerMod[2, #, Prime[First[#2]]] &, Join[{0, 1}, Select[Range[100], CompositeQ]]] (* Paolo Xausa, Jul 01 2024 *)

PROG

(PARI) c=-1; forprime(p=1, 999, while(isprime(c++), ); print1(lift( Mod(2, p)^c )", ")) \\ M. F. Hasler, Nov 29 2010

CROSSREFS