A007644 Primes not of form | 3^a +- 2^b | where a, b are nonnegative integers.

53, 71, 103, 107, 109, 149, 151, 157, 163, 167, 173, 181, 191, 193, 197, 199, 223, 233, 263, 271, 277, 281, 293, 311, 313, 317, 331, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491

Offset: 1

Author

N. J. A. Sloane, Mira Bernstein, Robert G. Wilson v

Keywords

• nonn

Comments

Contains all primes congruent to 53, 77 or 103 modulo 120. - Jianing Song, Feb 15 2020

Examples

			127 = 2^7 - 3^0, so 127 is not a member.
257 = 3^0 + 2^8, so 257 is not a member.
		

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• H. Gauchman and I. Rosenholtz (Proposers), R. Martin (Solver), Difference of prime powers, Problem 1404, Math. Mag., 65 (No. 4, 1992), 265; Solution, Math. Mag., 66 (No. 4, 1993), 269.

Crossrefs

Cf. A007643, A004051, A103146.

Extensions

Minor edits by N. J. A. Sloane, Jun 27 2010

More terms from Jon E. Schoenfield, Jun 30 2010