A129244 Least K such that K*(prime(10*n)^(10*n))-1 is prime with prime(n)=n-th prime.

14, 20, 200, 98, 42, 132, 908, 432, 1040, 290, 48, 224, 1370, 462, 146, 110, 398, 402, 152, 264, 770, 1322, 3030, 692, 1106, 2840, 1680, 1328, 7752, 5180, 1520, 1868, 578, 1064, 1286, 3692, 2282, 1158, 1832, 3438, 98, 3204, 824, 2162, 1874, 3410, 1754, 3014, 1988, 992

Offset

1,1

Links

Michael S. Branicky, Table of n, a(n) for n = 1..264

Mathematica

s={}; Do[k=0; Until[PrimeQ[k*Prime[10n]^(10n)-1], k++]; AppendTo[s, k], {n, 39}]; s (* James C. McMahon, Jan 17 2025 *)

Prog

(PARI) a(n) = {my(k=1); while (!ispseudoprime(k*(prime(10*n)^(10*n))-1), k++); k; } \\ Michel Marcus, Sep 16 2019

Crossrefs

Cf. A129243, A129245.

Sequence in context: A377904 A064974 A167335 * A070719 A030643 A303475

Adjacent sequences: A129241 A129242 A129243 * A129245 A129246 A129247

Keyword

nonn

Author

Pierre CAMI, Apr 05 2007

Extensions

a(26)-a(39) from James C. McMahon, Jan 17 2025

a(40)-a(50) from Michael S. Branicky, Jan 19 2025

Status

approved