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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

%I

%S 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,

%T 81,83,101,103,107,109,125,127,137,139,149,151,167,169,179,181,191,

%U 193,197,199,227,229,239,241,243,269,271,281,283,311,313,347,349,359

%N Union of all numbers {p, q} where p and q are both primes or powers of primes and q = p+2.

%D 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.

%H T. D. Noe, <a href="/A001092/b001092.txt">Table of n, a(n) for n = 1..10000</a>

%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.nrbook.com/abramowitz_and_stegun/">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

%o (PARI) {isprimepower(n)=matsize(factor(n))[1]==1} for(n=1,400,if(isprimepower(n)&&(isprimepower(n-2)||isprimepower(n+2)),print1(n","))) (from Ralf Stephan, Aug 20 2004)

%Y Cf. A053702, A074852.

%K nonn,easy

%O 1,2

%A _N. J. A. Sloane_.

%E Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jun 14, 2001

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