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 A333788 #11 Apr 15 2020 21:08:25 %S A333788 9,15,25,51,85,289,771,1285,4369,66049,196611,327685,1114129,16843009, %T A333788 4295098369 %N A333788 Semiprimes whose both factors are Fermat primes. %C A333788 Product of two, not necessarily distinct Fermat primes. %C A333788 For the finiteness or non-finiteness of this sequence, see A019434. %C A333788 Most terms are binary palindromes (in A006995), except among the fifteen known terms, these squares > 9 are not: 25, 289, 66049, 4295098369. %Y A333788 Cf. A006995, A019434. %Y A333788 Subsequence of A334102. %K A333788 nonn %O A333788 1,1 %A A333788 _Antti Karttunen_, Apr 15 2020