A007644 - OEIS

A007644

Primes not of form | 3^a +- 2^b | where a, b are nonnegative integers.
(Formerly M5307)

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

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OFFSET

1,1

COMMENTS

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

REFERENCES

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

LINKS

Table of n, a(n) for n=1..52.

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.

EXAMPLE

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

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

CROSSREFS

Cf. A007643, A004051, A103146.

Sequence in context: A301479 A244187 A045807 * A136073 A133187 A057667

Adjacent sequences: A007641 A007642 A007643 * A007645 A007646 A007647

KEYWORD

nonn

AUTHOR

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

EXTENSIONS

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

More terms from Jon E. Schoenfield, Jun 30 2010

STATUS

approved