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A087489 Primes n such that 3^n-2^n is composite. 2
7, 11, 13, 19, 23, 37, 41, 43, 47, 61, 67, 71, 73, 79, 83, 89, 97, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 281, 283, 293, 307, 311, 313, 317 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 2..1000

MATHEMATICA

Select[Prime[Range[100]], CompositeQ[3^#-2^#]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Feb 18 2018 *)

PROG

(PARI) apmb(a, b, n) = { forprime(x=2, n, y=a^x-b^x; if(!ispseudoprime(y), print1(x", "); ) ) }

CROSSREFS

Sequence in context: A165349 A160024 A063911 * A155488 A100350 A084467

Adjacent sequences:  A087486 A087487 A087488 * A087490 A087491 A087492

KEYWORD

nonn

AUTHOR

Cino Hilliard, Oct 26 2003

STATUS

approved

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Last modified September 15 20:42 EDT 2019. Contains 327087 sequences. (Running on oeis4.)