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 A217994 a(n) = 2^((2 + n + n^2)/2). 1
 2, 4, 16, 128, 2048, 65536, 4194304, 536870912, 137438953472, 70368744177664, 72057594037927936, 147573952589676412928, 604462909807314587353088 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..80 FORMULA a(n) = a(n-1)*(2^n), with a(0)=2. G.f.: G(0)/x -1/x, where G(k)= 1 + 2^k*x/(1 - x/(x + x/G(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Jul 26 2013 EXAMPLE a(3) = 128 because a(3) = 2^(2 + 3 + 3^2)/2 = 2^14/2 = 2^7 = 128. MATHEMATICA Table[2^((2 + n + n^2) / 2), {n, 0, 30}] (* Vincenzo Librandi, Jul 26 2013 *) PROG (Maxima) A217994[n]:=2^((2+n+n^2)/2)\$ makelist(A217994[n], n, 0, 30); /* Martin Ettl, Oct 29 2012 */ (PARI) a(n)=2<<((n+n^2)/2) \\ Charles R Greathouse IV, Jan 06 2013 (Magma) [2^((2 + n + n^2) div 2): n in [0..15]]; // Vincenzo Librandi, Jul 26 2013 CROSSREFS Sequence in context: A009200 A144526 A179532 * A174677 A073924 A061588 Adjacent sequences: A217991 A217992 A217993 * A217995 A217996 A217997 KEYWORD nonn,easy AUTHOR Mokhtar Mohamed, Oct 19 2012 STATUS approved

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Last modified March 23 10:25 EDT 2023. Contains 361443 sequences. (Running on oeis4.)