A078656 a(n) = prime(k) where k = n-th prime congruent to 1 mod 10.

31, 127, 179, 283, 353, 547, 739, 877, 1087, 1153, 1297, 1523, 1597, 1741, 1823, 2063, 2221, 2749, 2909, 3001, 3259, 3517, 3733, 3911, 4153, 4421, 4663, 4759, 4943, 5189, 5281, 5701, 5801, 6229, 6311, 6841, 7109

Offset: 1

Author

Cino Hilliard, Dec 14 2002

Keywords

• easy
• nonn

Links

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

Crossrefs

Cf. A024912.

Programs

Mathematica

Prime[10Select[Range[110], PrimeQ[10# + 1] &] + 1]
Prime[#]&/@Select[Prime[Range[200]],NumberDigit[#,0]==1&] (* Requires Mathematica version 12 or later *) (* Harvey P. Dale, May 31 2021 *)

PARI

pip(n,m,r) = {sr=0; forprime(x=3,n, if(x%m == r,v=prime(x); sr+=1.0/v; print1(v" "); ) ); print(); print("m="m" r="r" sr="sr); }

Extensions

Edited by Robert G. Wilson v, Dec 17 2002