This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A232460 #22 Jul 20 2022 01:30:11 %S A232460 -3,-1,11,251,65531,4294967291,18446744073709551611, %T A232460 340282366920938463463374607431768211451, %U A232460 115792089237316195423570985008687907853269984665640564039457584007913129639931 %N A232460 a(n) = 2^(2^n) - 5. %C A232460 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 A232460 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 A232460 a(n) = A000215(n) - 6. %F A232460 a(0) = - 3; a(n) = (a(n-1) + 5)^2 - 5, n >= 1. %t A232460 Table[2^(2^n) - 5, {n, 0, 8}] %o A232460 (Magma) [2^(2^n)-5 : n in [0..8]] %o A232460 (PARI) for(n=0, 8, print1(2^(2^n)-5, ", ")); %o A232460 (Python) %o A232460 def A232460(n): return (1<<(1<<n))-5 # _Chai Wah Wu_, Jul 19 2022 %Y A232460 Cf. A006285. %K A232460 sign,easy %O A232460 0,1 %A A232460 _Arkadiusz Wesolowski_, Nov 24 2013