

A039954


Palindromic primes formed from the reflected decimal expansion of Pi.


8




OFFSET

1,1


COMMENTS

Carlos Rivera reports that the next two members of this sequence have 301 and 921 digits. The first has been tested with APRTECLE. The second one is only a StrongPseudoPrime at the moment.  May 16 2003
Thomas Spahni reports that the fifth member of this sequence with 921 digits is prime. He used Francois Morain's ECPPV6.4.5a which proved primality in 14913.7 seconds running on a Celeron Core2 CPU at 2.00GHz.  Jun 05 2008
Primes in A135697. Terms with an odd number of digits are the primes in A135698.  Omar E. Pol, Mar 06 2012


LINKS

Table of n, a(n) for n=1..3.
C. K. Caldwell, Prime Curios, 31414...51413 (53digits)
Eric Weisstein's World of Mathematics, Palindromic Prime.


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 *)


CROSSREFS

Cf. A002385, A119351.
Sequence in context: A083974 A135698 A088102 * A134215 A034994 A139541
Adjacent sequences: A039951 A039952 A039953 * A039955 A039956 A039957


KEYWORD

base,nonn,bref


AUTHOR

G. L. Honaker, Jr.


STATUS

approved



