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 A282565 #21 Feb 20 2017 00:30:36 %S A282565 3,5,13,29,43,113,223,509,907,2003,4051,8171,16333,32603,65437,130649, %T A282565 262027,524261,1048507,2097047,4194277,8388209,16776481,33554201, %U A282565 67108753,134217401,268435273,536869631,1073741719,2147483549,4294966477,8589934307,17179868383 %N A282565 a(n) is the largest prime p < 2^n such that p + 2^n is also prime. %e A282565 13 + 16 (2^4) = 29 (prime). %e A282565 29 + 32 (2^5) = 61 (prime). %e A282565 43 + 64 (2^6) = 107 (prime). %Y A282565 Cf. A000040, A000079. %K A282565 nonn %O A282565 2,1 %A A282565 _Emre APARI_, Feb 18 2017