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 A183185 Numbers n such that 10^(2n+1)-5*10^n-1 is prime. 1
 14, 22, 36, 104, 1136, 17864, 25448 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9. LINKS Patrick De Geest, World!Of Numbers, Palindromic Wing Primes (PWP's) Makoto Kamada, Prime numbers of the form 99...99499...99 FORMULA a(n) = (A077782(n)-1)/2. MATHEMATICA Do[If[PrimeQ[10^(2n + 1) - 5*10^n - 1], Print[n]], {n, 3000}] PROG (PARI) is(n)=ispseudoprime(10^(2*n+1)-5*10^n-1) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Cf. A004023, A077775-A077798, A107123-A107127, A107648, A107649, A115073, A183174-A183187. Sequence in context: A187776 A048196 A225710 * A259750 A211416 A045282 Adjacent sequences:  A183182 A183183 A183184 * A183186 A183187 A183188 KEYWORD nonn,base AUTHOR Ray Chandler, Dec 28 2010 STATUS approved

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Last modified September 23 21:14 EDT 2017. Contains 292391 sequences.