A191617 Least number a such that (2^n+a)*2^n + 1 is a prime number.

0, 0, 1, 0, 4, 3, 12, 0, 1, 3, 6, 6, 16, 9, 4, 5, 3, 20, 6, 5, 4, 5, 21, 9, 16, 35, 6, 6, 18, 8, 28, 6, 46, 11, 39, 6, 3, 20, 22, 47, 93, 90, 13, 51, 27, 98, 34, 6, 12, 14, 21, 21, 49, 143, 18, 5, 58, 30, 37, 30, 6, 56, 16, 150, 72, 59, 12, 5, 34, 3, 28, 45

Offset: 1

Author

Pierre CAMI, Jun 09 2011

Keywords

• nonn

Links

• Pierre CAMI, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A191618, A191619, A191620, A191621.

Programs

Mathematica

Table[a = 0; While[! PrimeQ[(2^n + a)*2^n + 1], a++]; a, {n, 100}] (* T. D. Noe, Jun 11 2011 *)