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2^p - 7 where p is prime.
3

%I #12 Sep 08 2022 08:45:15

%S -3,1,25,121,2041,8185,131065,524281,8388601,536870905,2147483641,

%T 137438953465,2199023255545,8796093022201,140737488355321,

%U 9007199254740985,576460752303423481,2305843009213693945,147573952589676412921,2361183241434822606841

%N 2^p - 7 where p is prime.

%H Vincenzo Librandi, <a href="/A098815/b098815.txt">Table of n, a(n) for n = 1..200</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/RamanujansSquareEquation.html">Ramanujan's Square Equation</a>

%e If p = 3, then 2^3 - 7 = 1.

%e If p = 5, then 2^5 - 7 = 25.

%t Table[2^Prime[n] - 7, {n, 20}]

%o (Magma) [2^p-7: p in PrimesUpTo(100)]; // _Vincenzo Librandi_, Apr 29 2014

%K sign

%O 1,1

%A _Parthasarathy Nambi_, Oct 07 2004

%E More terms from _Ray Chandler_, Nov 14 2004