A022462 a(n) = prime(n)*prime(n+2) mod prime(n+1).

1, 1, 6, 3, 5, 9, 11, 22, 17, 19, 13, 33, 35, 23, 17, 47, 49, 43, 63, 61, 55, 59, 41, 65, 93, 95, 99, 101, 57, 71, 107, 125, 119, 129, 139, 121, 139, 143, 137, 167, 161, 171, 185, 189, 175, 67, 175, 219, 221, 209, 227, 221, 191, 221, 227, 257, 259, 253, 273, 263

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A090076, A073271, A000040.

Programs

Magma

[NthPrime(n)*NthPrime(n+2) mod NthPrime(n+1): n in [1..50]]; // G. C. Greubel, Feb 28 2018

Mathematica

Table[Mod[Prime[n]Prime[n+2], Prime[n+1]], {n, 1, 50}] (* G. C. Greubel, Feb 28 2018 *)

PARI

a(n) = (prime(n)*prime(n+2)) % prime(n+1); \\ Michel Marcus, Sep 30 2013

Formula

a(n) = A090076(n) modulo A000040(n+1). - Michel Marcus, Sep 30 2013

Conjecture: a(n) = prime(n)*prime(n+2) - prime(n+1)*(prime(n) + prime(n+2) - prime(n+1) - 1), except for a(3) and a(8). - Ridouane Oudra, Oct 26 2021

Extensions

Edited by Reinhard Zumkeller, Jul 22 2002