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A001092
Union of all numbers {p, q} where p and q are both primes or powers of primes and q = p+2.
1
1, 2, 3, 4, 5, 7, 9, 11, 13, 17, 19, 23, 25, 27, 29, 31, 41, 43, 47, 49, 59, 61, 71, 73, 79, 81, 83, 101, 103, 107, 109, 125, 127, 137, 139, 149, 151, 167, 169, 179, 181, 191, 193, 197, 199, 227, 229, 239, 241, 243, 269, 271, 281, 283, 311, 313, 347, 349, 359
OFFSET
1,2
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 844.
LINKS
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
PROG
(PARI) {isprimepower(n)=matsize(factor(n))[1]==1} for(n=1, 400, if(isprimepower(n)&&(isprimepower(n-2)||isprimepower(n+2)), print1(n", "))) \\ Ralf Stephan, Aug 20 2004
CROSSREFS
Sequence in context: A284288 A343983 A074583 * A327782 A000430 A166684
KEYWORD
nonn,easy
EXTENSIONS
Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jun 14 2001
STATUS
approved