login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A022457 a(n) = prime(2n) mod prime(n). 5
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 20 03:20 EDT 2021. Contains 345157 sequences. (Running on oeis4.)