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 A121979 #13 Aug 28 2025 17:15:46
%S A121979 1,11,12,20,24,27,28,34,40,44,61,74,79,82,95,96,119,131,136,147,148,
%T A121979 156,164,170,173,180,187,209,211,238,252,255,269,279,299,328,337,340,
%U A121979 343,371,379,380,388,397,413,452,462,473,476,483,516,522,527,530,539,572
%N A121979 Numbers k such that (2*k^2)^4 + 1 is prime.
%C A121979 Corresponding primes of the form (2*k^2)^4 + 1 are {17, 3429742097, 6879707137, 409600000001, ...}.
%C A121979 There are consecutive twin pairs {a(n),a(n+1)} = {11,12}, {27,28}, {95,96},{147,148}, ...
%H A121979 G. C. Greubel, <a href="/A121979/b121979.txt">Table of n, a(n) for n = 1..5000</a>
%t A121979 Select[Range[1000],PrimeQ[(2*#1^2)^4+1]&]
%o A121979 (PARI) is(n)=isprime((2*n^2)^4+1) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y A121979 Cf. A000068.
%K A121979 nonn,easy,changed
%O A121979 1,2
%A A121979 _Alexander Adamchuk_, Sep 10 2006