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 A107083 Integers n such that 10^n + 31 is prime. 25
 1, 2, 3, 14, 18, 44, 54, 89, 469, 2060, 2985, 6197, 16452, 19393, 21205, 49657, 74670, 76374 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The next term, if one exists, is >100000. - Robert Price, Apr 26 2011 See Kamada link - primecount.txt for terms, primesize.txt for discovery details including proofs of primality - search on "10031". LINKS Makoto Kamada, List of near-repdigit-related prime numbers. EXAMPLE For n = 3 we get 10^3 + 31 = 1000 + 31 = 1031, which is prime. MATHEMATICA a={}; Do[If[PrimeQ[p=10^n+31], AppendTo[a, n]], {n, 0, 6*10^2}]; a (* Vladimir Joseph Stephan Orlovsky, Aug 07 2008 *) CROSSREFS Cf. A049054, A088274, A088275, A095688, A108052, A108050, A108049, A108054. Sequence in context: A041010 A041733 A212112 * A266694 A284928 A294405 Adjacent sequences:  A107080 A107081 A107082 * A107084 A107085 A107086 KEYWORD more,nonn,changed AUTHOR Julien Peter Benney (jpbenney(AT)ftml.net), Jun 08 2005 EXTENSIONS 16452 and 19393 from Robert Price, Mar 22 2010 Additional term (21205) from Robert Price, May 24 2010 Missing term (6197) added by Robert Price, Dec 07 2010 Edited by Ray Chandler, Dec 23 2010 a(16)=49657 from Robert Price, Dec 31 2010 a(17)=74670 from Robert Price, Jan 29 2011 a(18)=76374 from Robert Price, Mar 03 2011 STATUS approved

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Last modified January 18 00:34 EST 2019. Contains 319255 sequences. (Running on oeis4.)