A023152 Numbers k such that prime(k) == 10 (mod k).

1, 7, 19, 21, 2703, 15929, 4124583, 27067051, 179992913, 179993011, 179993159, 1208198559, 1208198859, 55762149031, 382465573511, 382465573547, 18262325820337, 6201265271239229, 6201265271239409, 6201265271239433, 43525513764814941, 43525513764816369, 43525513764816411, 43525513764816437, 306268030480171419

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Crossrefs

Cf. A092052, A023143, A023144, A023145, A023146, A023147, A023148, A023149, A023150, A023151.

Programs

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; p = 1; Do[ If[ Mod[p = NextPrim[p], n] == 10, Print[n]], {n, 1, 10^9}] (* Robert G. Wilson v, Feb 18 2004 *)

PARI

n=0; forprime(p=2,1e9, if(Mod(p,n++)==10, print1(n", "))) \\ Charles R Greathouse IV, Apr 29 2015

Sage

def A023152(max) :
    terms = []
    p = 2
    for n in range(1,max+1) :
        if (p - 10) % n == 0 : terms.append(n)
        p = next_prime(p)
    return terms
# Eric M. Schmidt, Feb 05 2013

Extensions

Extended by Robert G. Wilson v, Feb 18 2004

a(9)-a(14) from Robert G. Wilson v, Feb 22 2006

First two terms inserted by Eric M. Schmidt, Feb 05 2013

a(15)-a(25) from Giovanni Resta, Feb 23 2020