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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
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".
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 *)
KEYWORD
more,nonn
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