1,1

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mod[Prime[Range[100]], 21]

(MAGMA) [p mod(21): p in PrimesUpTo(500)];

(PARI) a(n) = prime(n) % 21; \\ Michel Marcus, May 05 2014

(Sage) [mod(p, 21) for p in primes(500)] # Bruno Berselli, May 05 2014

Cf. similar sequences listed in A242119.

Sequence in context: A229786 A242122 A074721 * A242120 A259277 A152073

Adjacent sequences: A242118 A242119 A242120 * A242122 A242123 A242124

nonn,easy

Vincenzo Librandi, May 05 2014

approved