A022457 a(n) = prime(2n) mod prime(n).

1, 1, 3, 5, 7, 11, 9, 15, 15, 13, 17, 15, 19, 21, 19, 25, 21, 29, 29, 31, 35, 35, 33, 45, 35, 37, 45, 49, 53, 55, 39, 49, 43, 59, 51, 57, 59, 57, 63, 63, 63, 71, 61, 71, 69, 81, 69, 57, 67, 83, 91, 91, 95, 91, 87, 87, 81, 99, 93, 97, 107, 97, 87, 97, 107, 109, 95

Offset

1,3

Links

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

Formula

a(n) = A031215(n) modulo A000040(n). - Michel Marcus, Sep 30 2013

Maple

A022457 := proc(n)
    modp(ithprime(2*n), ithprime(n)) ;
end proc:
seq(A022457(n), n=1..67) ; # R. J. Mathar, Sep 02 2016

Mathematica

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

Prog

(PARI) a(n) = prime(2*n) % prime(n); \\ Michel Marcus, Sep 30 2013
(Magma) [NthPrime(2*n) mod NthPrime(n): n in [1..50]]; // G. C. Greubel, Feb 28 2018

Crossrefs

Cf. A000040, A031215, A066066.

Sequence in context: A174839 A245462 A338842 * A066066 A241957 A112070

Adjacent sequences: A022454 A022455 A022456 * A022458 A022459 A022460

Keyword

nonn

Author

Clark Kimberling

Status

approved