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%I #24 Sep 01 2019 11:01:07
%S 1,3,3,5,3,3,3,15,5,3,3,3,5,57,35,5,41,5,45,87,11,17,21,59,27,47,33,5,
%T 27,93,57,59,5,23,35,93,35,15,11,65,57,35,35,299,33,83,3,17,51,15,33,
%U 17,117,59,21,75,11,3,5,119,3,59,137,159,5,347,45,113,105,27,111
%N a(n) = 4^n - prevprime(4^n).
%H Daniel Starodubtsev, <a href="/A013606/b013606.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A000302(n) - A104089(n). - _Michel Marcus_, Sep 01 2019
%p seq(4^i-prevprime(4^i),i=1..100);
%t #-NextPrime[#,-1]&/@(4^Range[80]) (* _Harvey P. Dale_, Dec 13 2016 *)
%o (PARI) a(n) = 4^n - precprime(4^n); \\ _Michel Marcus_, Sep 01 2019
%Y Cf. A000302, A104089.
%K nonn
%O 1,2
%A James Kilfiger (mapdn(AT)csv.warwick.ac.uk)