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 A098640 2^p + 1 where p is prime. 9
 5, 9, 33, 129, 2049, 8193, 131073, 524289, 8388609, 536870913, 2147483649, 137438953473, 2199023255553, 8796093022209, 140737488355329, 9007199254740993, 576460752303423489, 2305843009213693953 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..200 EXAMPLE If p=2, 2^2+1 = 5. If p=7, 2^7+1 = 129. MATHEMATICA Table[2^Prime[n] + 1, {n, 18}] (* Robert G. Wilson v, Nov 01 2004 *) PROG (MAGMA) [2^p+1: p in PrimesUpTo(100)]; // Vincenzo Librandi, Apr 29 2014 CROSSREFS Sequence in context: A116390 A028351 A211952 * A239546 A083832 A070969 Adjacent sequences:  A098637 A098638 A098639 * A098641 A098642 A098643 KEYWORD nonn,easy AUTHOR Parthasarathy Nambi, Oct 27 2004 EXTENSIONS More terms from Robert G. Wilson v, Nov 01 2004 STATUS approved

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Last modified December 13 23:14 EST 2019. Contains 329974 sequences. (Running on oeis4.)