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 A020674 #30 Aug 02 2025 08:28:19 %S A020674 0,2,5,7,8,13,18,20,22,23,28,32,37,38,45,47,50,52,53,55,63,70,72,77, %T A020674 80,82,88,92,95,98,103,112,117,118,125,127,128,130,133,143,148,152, %U A020674 157,162,167,173,175,178,180,182,188,197,198,200,205,207,208,212,220,223,230,242 %N A020674 Numbers of the form 2*x^2 + 5*y^2. %H A020674 Vincenzo Librandi, <a href="/A020674/b020674.txt">Table of n, a(n) for n = 1..7000</a> (corrected by _Sean A. Irvine_, Jun 07 2019) %H A020674 N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references) %t A020674 Union[2*First[#]+5*Last[#]&/@(Tuples[Range[0,10],2]^2)] (* _Harvey P. Dale_, May 09 2012 *) %Y A020674 Cf. A000286, A106889 (primes). %K A020674 easy,nonn %O A020674 1,2 %A A020674 _David W. Wilson_