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%I #20 Sep 08 2022 08:45:33
%S 3,10,40,544,2560,34816,163840,2228224,136314880,671088640,
%T 34896609280,584115552256,2748779069440,37383395344384,
%U 2286984185774080,146366987889541120,720575940379279360,37469948899722526720,627189298506124754944
%N a(n) = (2^prime(n) + 2^prime(n+1)) / 4.
%C Note that 4 is 2^prime(1).
%H G. C. Greubel, <a href="/A137781/b137781.txt">Table of n, a(n) for n = 1..460</a>
%F From _Wesley Ivan Hurt_, Mar 27 2015: (Start)
%F a(n) = A137389(n)/4.
%F a(n) = (A034785(n) + A034785(n+1))/4. (End)
%p A137781:=n->(2^ithprime(n)+2^ithprime(n+1))/4: seq(A137781(n), n=1..20); # _Wesley Ivan Hurt_, Mar 27 2015
%t Table[(2^Prime[n] + 2^Prime[n + 1])/4, {n, 20}] (* _Wesley Ivan Hurt_, Mar 27 2015 *)
%t (2^#[[1]]+2^#[[2]])/4&/@Partition[Prime[Range[20]],2,1] (* _Harvey P. Dale_, Dec 21 2019 *)
%o (Magma) [(2^NthPrime(n) + 2^NthPrime(n+1)) / 4: n in [1..20]]; // _Vincenzo Librandi_, Mar 28 2015
%o (PARI) vector(15,n,(2^prime(n)+2^prime(n+1))/4) \\ _Derek Orr_, Mar 29 2015
%Y Cf. A034785, A137389.
%K nonn,easy
%O 1,1
%A _Alexander R. Povolotsky_, Apr 28 2008
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