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 A216148 #23 Apr 03 2023 10:36:13 %S A216148 3,17832200896513,78692816150593075150849 %N A216148 Primes of the form 2*k^k + 1 = A216147(k). %C A216148 The sequence should be extended through A110932, which lists the corresponding values of k: The next term, 2*251^251 + 1 = A216147(A110932(4)) ~ 4.16*10^602, is too large to include here. %H A216148 M. F. Hasler, <a href="/A216148/b216148.txt">Table of n, a(n) for n = 1..4</a> %H A216148 C. Caldwell, G.L. Honaker (Eds), <a href="https://t5k.org/curios/page.php/78692816150593075150849.html">Prime Curios!: 78692816150593075150849</a>. %H A216148 "Jim", <a href="http://mathforum.org/kb/message.jspa?messageID=544888">Topic: The Lost Proof of Fermat</a>, on mathforum.org, Jan 31 2004 %F A216148 a(2) = A216147(12) = A005109(95) = A070855(12) = A058383(89) = A133663(18). %F A216148 a(3) = A216147(18) = A005109(183)= A070855(18) = A058383(177)= A133663(36). %t A216148 Select[Table[2n^n+1,{n,20}],PrimeQ] (* _Harvey P. Dale_, Mar 27 2016 *) %o A216148 (PARI) for(n=1,999, ispseudoprime(p=n^n*2+1) & print1(p",")) %Y A216148 Cf. A110932. %Y A216148 A subsequence of A133663, with b=a and c=1. %K A216148 nonn,bref,less %O A216148 1,1 %A A216148 _M. F. Hasler_, Sep 02 2012