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 A125020 #8 Mar 12 2020 07:22:55 %S A125020 0,2,11,12,20,29,30,38,61,65,83,90,92,101,110,119,132,137,151,159,164, %T A125020 182,200,208,218,227,240,245,254,263,272,308,335,344,353,355,389,393, %U A125020 407,434,443,451,453,462,502,514,515,524,542,551,552,578,587,600,605,623 %N A125020 a(n) = (A124983(n)-1)/4. %H A125020 Amiram Eldar, <a href="/A125020/b125020.txt">Table of n, a(n) for n = 1..10000</a> %t A125020 Select[Range[0, 600], !PrimeQ[4*# + 1] && Length @ PowersRepresentations[4*# + 1, 2, 2] == 1 &] (* _Amiram Eldar_, Mar 12 2020 *) %Y A125020 Cf. A124983, A002145, A124982, A124983. %K A125020 nonn %O A125020 1,2 %A A125020 _Artur Jasinski_, Nov 16 2006 %E A125020 More terms from _Amiram Eldar_, Mar 12 2020