A174272 Exactly one of 2^n-3 and 2^n+3 is prime.
1, 2, 5, 7, 9, 10, 14, 15, 16, 18, 20, 22, 24, 28, 29, 30, 55, 67, 84, 94, 116, 122, 150, 174, 213, 221, 228, 233, 266, 336, 390, 452, 545, 689, 694, 784, 850, 1110, 1704, 1736, 2008, 2139, 2191, 2321, 2367, 2370, 3237, 3954, 4002, 4060, 4062, 4552, 5547, 5630
Offset: 1
Keywords
Examples
a(1)=1 because 2^1-3=-1 is nonprime and 2^1+3=5 is prime.
Extensions
Corrected by Charles R Greathouse IV, Mar 20 2010
Comments