A125113 Numbers n such that 2n-1, 4n-1, 8n-1, 16n-1, 32n-1 and 64n-1 are primes.

45, 31710, 63570, 202635, 405405, 534600, 561330, 589305, 666945, 799350, 903045, 979125, 1082115, 1122660, 1164735, 1303035, 1424475, 1620645, 1669995, 1892100, 1981020, 2044440, 2164230, 2222415, 2329470, 2332125, 2447445, 2448855

Offset: 1

Author

Artur Jasinski, Nov 22 2006

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A006254, A124485, A124493, A124494, A124017, A124514, A124515, A124516.

Programs

Mathematica

Select[15*Range[200000], And @@ PrimeQ /@ ({2, 4, 8, 16, 32, 64}*# - 1) &] (* Ray Chandler, Nov 22 2006 *)
Select[15*Range[164000],AllTrue[# 2^Range[6]-1,PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 20 2020 *)

Extensions

Extended by Ray Chandler, Nov 22 2006