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 A051439 #24 Mar 23 2024 11:42:56 %S A051439 3,5,11,23,59,137,313,727,1621,3673,8167,17881,38891,84047,180511, %T A051439 386117,821647,1742539,3681149,7754081,16290073,34136059,71378603, %U A051439 148948141,310248251,645155227,1339484207,2777105131,5750079077 %N A051439 a(n) = prime(2^n + 1). %H A051439 Hugo Pfoertner, <a href="/A051439/b051439.txt">Table of n, a(n) for n = 0..78</a>, using David Baugh's b-file from A033844. %H A051439 Kim Walisch, <a href="https://github.com/kimwalisch/primecount">Fast C++ prime counting function implementation</a>. %e A051439 a(0) = prime(2^0+1) = prime(2) = 3, %e A051439 a(1) = prime(2+1) = prime(3) = 5, %e A051439 a(2) = prime(2^2+1) = prime(5) = 11, %e A051439 a(3) = prime(2^3+1) = prime(9) = 23, and so on. - _N. J. A. Sloane_, Dec 09 2020 %t A051439 Prime[2^Range[0,30]+1] (* _Harvey P. Dale_, Jan 19 2014 *) %Y A051439 Cf. A000040, A033844, A018249, A051438, A051440. %K A051439 nonn %O A051439 0,1 %A A051439 _N. J. A. Sloane_ %E A051439 More terms from Michael Lugo (mlugo(AT)thelabelguy.com), Dec 22 1999