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%I #22 Jul 20 2022 01:30:11
%S -3,-1,11,251,65531,4294967291,18446744073709551611,
%T 340282366920938463463374607431768211451,
%U 115792089237316195423570985008687907853269984665640564039457584007913129639931
%N a(n) = 2^(2^n) - 5.
%C For n >= 3, a(n) is not of the form 2^k + p, where p is a prime. Therefore every term greater than 11 is in A006285 (de Polignac numbers).
%H Wacław Sierpiński, <a href="http://matwbn.icm.edu.pl/ksiazki/mon/mon42/mon4212.pdf">Elementary Theory of Numbers</a>, Monografie Matematyczne 42 (1964), p. 415.
%F a(n) = A000215(n) - 6.
%F a(0) = - 3; a(n) = (a(n-1) + 5)^2 - 5, n >= 1.
%t Table[2^(2^n) - 5, {n, 0, 8}]
%o (Magma) [2^(2^n)-5 : n in [0..8]]
%o (PARI) for(n=0, 8, print1(2^(2^n)-5, ", "));
%o (Python)
%o def A232460(n): return (1<<(1<<n))-5 # _Chai Wah Wu_, Jul 19 2022
%Y Cf. A006285.
%K sign,easy
%O 0,1
%A _Arkadiusz Wesolowski_, Nov 24 2013
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