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 A172411 Numbers n such that 2^n+9 and 2^n+27 are prime. 0
 1, 2, 5, 10 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS No further terms between 10 and 5000. - R. J. Mathar, Feb 07 2010 No further terms to 100000. Expected number of remaining terms: (zeta(2) - 1 - 1/4 - ... - 1/100000^2)/log^2 2 ~= 0.00002. - Charles R Greathouse IV, Mar 25 2010 LINKS FORMULA A057196 INTERSECT A157007 - R. J. Mathar, Feb 07 2010 EXAMPLE a(1)=1 because 2^1+3^2=11 and 2^1+3^3=29 are prime. MATHEMATICA Select[Range[10], AllTrue[2^#+{9, 27}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 28 2016 *) PROG (PARI) is(n)=isprime(2^n+9) && isprime(2^n+27) \\ Charles R Greathouse IV, Sep 06 2016 CROSSREFS Sequence in context: A188948 A334295 A083460 * A264784 A306679 A125974 Adjacent sequences:  A172408 A172409 A172410 * A172412 A172413 A172414 KEYWORD nonn,less AUTHOR Juri-Stepan Gerasimov, Feb 02 2010 STATUS approved

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Last modified June 30 02:06 EDT 2022. Contains 354913 sequences. (Running on oeis4.)