A242126 a(n) = n-th prime modulo 28.

2, 3, 5, 7, 11, 13, 17, 19, 23, 1, 3, 9, 13, 15, 19, 25, 3, 5, 11, 15, 17, 23, 27, 5, 13, 17, 19, 23, 25, 1, 15, 19, 25, 27, 9, 11, 17, 23, 27, 5, 11, 13, 23, 25, 1, 3, 15, 27, 3, 5, 9, 15, 17, 27, 5, 11, 17, 19, 25, 1, 3, 13, 27, 3, 5, 9, 23, 1, 11, 13, 17, 23

Offset: 1

Author

Vincenzo Librandi, May 05 2014

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. similar sequences listed in A242119.

Programs

Magma

[p mod(28): p in PrimesUpTo(500)];

Mathematica

Mod[Prime[Range[100]], 28]

Sage

[mod(p, 28) for p in primes(500)] # Bruno Berselli, May 05 2014

Formula

Sum_k={1..n} a(k) ~ 14*n. - Amiram Eldar, Dec 13 2024