A282565 a(n) is the largest prime p < 2^n such that p + 2^n is also prime.

3, 5, 13, 29, 43, 113, 223, 509, 907, 2003, 4051, 8171, 16333, 32603, 65437, 130649, 262027, 524261, 1048507, 2097047, 4194277, 8388209, 16776481, 33554201, 67108753, 134217401, 268435273, 536869631, 1073741719, 2147483549, 4294966477, 8589934307, 17179868383

Offset: 2

Author

Emre APARI, Feb 18 2017

Keywords

• nonn

Examples

			13 + 16 (2^4) = 29  (prime).
29 + 32 (2^5) = 61  (prime).
43 + 64 (2^6) = 107 (prime).
		

Crossrefs

Cf. A000040, A000079.