/* A 24-term relation communicated 23-July-2010 by Amrik Singh Nimbran: 22[1] = +407688507599[121409547033] +131623078258[138873731225] +597669985516[148431551771] -252429143056[168722145007] +862365372722[202954204459] +87197344668[221943811240] +834204536395[261002206018] +418763705566[269007136889] +756410649259[548275361132] -116186529925[656902304557] -257884015194[662573197307] +338026625427[1372432573478] -202652185491[2105653391693] +163956958098[3761284561432] -5430991987[5142102426318] +88783805991[5745192731179] +415733461899[10892900268195] -239380754897[17780261434697] +27932108979[38759264489343] -114027862098[165171481279982] +378900051128[169838669284032] -414020468150[772654028018543] -199714577789[1948025182233307] -280710519362[1976865441422893] Primes: {5, 13, 17, 29, 37, 41, 53, 61, 73, 89, 97, 101, 109, 137, 229, 257, 281, 353, 433, 461, 593, 601, 941} Note the prime 941 which was out of range with my 2006 search (using primes <=761) Verify the relation numerically with pari/gp via gp < arctan-24term-nimbran.gp (see end of file) */ \\default(echo,1); default(realprecision, 10000); \\ decimal digits default(format,"g.55"); A(x)=atan(1/x); { -22 * A(1) +407688507599 * A(121409547033) \\ 1 +131623078258 * A(138873731225) \\ 2 +597669985516 * A(148431551771) \\ 3 -252429143056 * A(168722145007) \\ 4 +862365372722 * A(202954204459) \\ 5 +87197344668 * A(221943811240) \\ 6 +834204536395 * A(261002206018) \\ 7 +418763705566 * A(269007136889) \\ 8 +756410649259 * A(548275361132) \\ 9 -116186529925 * A(656902304557) \\ 10 -257884015194 * A(662573197307) \\ 11 +338026625427 * A(1372432573478) \\ 12 -202652185491 * A(2105653391693) \\ 13 +163956958098 * A(3761284561432) \\ 14 -5430991987 * A(5142102426318) \\ 15 +88783805991 * A(5745192731179) \\ 16 +415733461899 * A(10892900268195) \\ 17 -239380754897 * A(17780261434697) \\ 18 +27932108979 * A(38759264489343) \\ 19 -114027862098 * A(165171481279982) \\ 20 +378900051128 * A(169838669284032) \\ 21 -414020468150 * A(772654028018543) \\ 22 -199714577789 * A(1948025182233307) \\ 23 -280710519362 * A(1976865441422893) \\ 24 } quit; /* Test run: % gp < arctan-24term-nimbran.gp -1.9778779060308370354 E-10017 ? quit; */