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 A269928 #8 Jan 05 2025 19:51:40
%S A269928 1,3,5,12,15,24,40,48,60,120,240,360,420,720,840,1560,1680,2520,3360,
%T A269928 5040,8400,9240,10920,15120,18480,21840,27720,32760,36960,43680,55440,
%U A269928 65520,109200,110880,120120,166320,196560,221760,240240,360360,480480,720720,1113840
%N A269928 Integers n that belong to more Pythagorean triples than preceding integers.
%C A269928 Called optimal P-numbers in Tripathi link.
%H A269928 A. Tripathi, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Papers1/46_47-4/Tripathi.pdf">On Pythagorean triples containing a fixed integer</a>, Fib. Q., 46/47 (2008/2009), 331-340. See Theorem 11.
%H A269928 <a href="/index/Ps#PyTrip">Index entries related to Pythagorean Triples.</a>
%o A269928 (PARI) nbpt(n) = {oddn = n/(2^valuation(n, 2)); f = factor(oddn); for (k=1, #f~, if ((f[k,1] % 4) != 1, f[k,2] = 0);); n1 = factorback(f); if (n % 2, (numdiv(n^2)+numdiv(n1^2))/2 -1, (numdiv((n/2)^2)+numdiv(n1^2))/2 -1);}
%o A269928 lista(nn) = {last = -1; for (n=1, nn, if ((new = nbpt(n)) > last, print1(n, ", "); last = new;););}
%Y A269928 Cf. A046081, A269929.
%K A269928 nonn
%O A269928 1,2
%A A269928 _Michel Marcus_, Mar 08 2016