A192542 Numbers n such that the interval [2^n-n, 2^n] is prime-free.

15, 25, 27, 28, 30, 34, 38, 40, 43, 45, 47, 48, 49, 51, 53, 55, 60, 71, 72, 75, 88, 97, 99, 106, 113, 117, 126, 128, 132, 139, 145, 146, 148, 151, 154, 168, 169, 175, 176, 177, 185, 186, 192, 208, 216, 223, 227, 232, 240, 253, 259

Offset: 1

Author

Juri-Stepan Gerasimov, Jul 03 2011

Keywords

• nonn

Comments

Places n where A192064(n)=0.

The numbers not in the sequence are characterized in A000043, A050414, A059608, A059610, etc.

Crossrefs

Cf. A192064.

Programs

Mathematica

Select[Range[260],NextPrime[2^#-#]>2^#&] (* Harvey P. Dale, Apr 08 2013 *)

PARI

is(n)=nextprime(2^n-n)>2^n \\ Charles R Greathouse IV, Jun 13 2017

Extensions

Corrected (a(16)=55 inserted) by Harvey P. Dale, Apr 08 2013