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A039954
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Palindromic primes formed from the reflected decimal expansion of Pi.
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6
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OFFSET
| 1,1
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COMMENTS
| Thomas Spahni reports that the fifth member of this sequence with 921 digits is prime. He used Francois Morain's ECPP-V6.4.5a which proved primality in 14913.7 seconds running on a Celeron Core2 CPU at 2.00GHz. Jun 05 2008.
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LINKS
| Source
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
C. K. Caldwell, Prime Curios, 31414...51413 (53-digits)
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MATHEMATICA
| Select[Table[p = Flatten[RealDigits[Pi, 10, d]]; (FromDigits[p] - 1)*10^(Length[p] - 3) + FromDigits[Drop[Reverse[p], 2]], {d, 27}], PrimeQ] (* Arkadiusz Wesolowski, Dec 18 2011 *)
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CROSSREFS
| Cf. A002385.
Cf. A002385, A119351.
Sequence in context: A083974 A135698 A088102 * A134215 A034994 A139541
Adjacent sequences: A039951 A039952 A039953 * A039955 A039956 A039957
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KEYWORD
| base,nonn,bref
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AUTHOR
| G. L. Honaker, Jr. (honak3r(AT)gmail.com)
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EXTENSIONS
| Carlos B. Rivera (crivera(AT)primepuzzles.net) reports that the next two members of this sequence have 301 and 921 digits. The first has been tested with APRTE-CLE. The second one is only a StrongPseudoPrime at the moment.
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