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 A253968 Numbers n such that (23*10^n - 26)/6 is prime. 1
 2, 4, 6, 10, 11, 18, 29, 151, 920, 1456, 1716, 1915, 4148, 4403, 8005, 9600, 41945, 47238 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE n = 2, 4, and 6, yield (23*10^n - 26)/6 = 379, 38329, and 3833329, respectively, which are prime. MATHEMATICA fQ[n_] := PrimeQ[(23*10^n - 26)/6]; Select[ Range@ 10000, fQ] (* Robert G. Wilson v, Jan 28 2015 *) PROG (PARI) is(n)=ispseudoprime((23*10^n-26)/6) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Cf. A254005. Sequence in context: A027435 A014666 A067852 * A102025 A226295 A090127 Adjacent sequences:  A253965 A253966 A253967 * A253969 A253970 A253971 KEYWORD nonn,more AUTHOR Hans Havermann, Jan 24 2015 STATUS approved

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Last modified April 19 18:34 EDT 2019. Contains 322286 sequences. (Running on oeis4.)