A101797 16n-1 such that 4n-1, 8n-1, 16n-1 and 32n-1 are primes.

719, 1439, 10799, 14159, 48479, 68639, 109919, 214559, 231359, 253679, 285599, 298799, 329999, 350159, 405599, 429119, 430799, 451679, 488399, 491279, 507359, 508559, 533999, 557759, 666959, 671039, 918959, 1014719, 1017119, 1148879

Offset

1,1

Links

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

Example

4*45-1=179, 8*45-1=359, 16*45-1=719 and 32*45-1=1439 are primes, so the first entry is 719.

Mathematica

16#-1&/@Select[Range[80000], AllTrue[#*2^Range[2, 5]-1, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 25 2015 *)

Crossrefs

Cf. A002515, A101794, A101795, A101796, A101798.

Sequence in context: A351669 A361345 A081425 * A144767 A127227 A139177

Adjacent sequences: A101794 A101795 A101796 * A101798 A101799 A101800

Keyword

easy,nonn

Author

Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 16 2004

Status

approved