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 A097752 #17 Dec 10 2016 21:23:08
%S A097752 1,2,3,4,5,6,8,9,10,12,15,16,18,20,21,24,25,27,30,32,36,40,42,45,48,
%T A097752 50,54,60,63,64,65,72,75,80,81,84,90,96,100,105,108,120,125,126,128,
%U A097752 130,135,144,150,160,162,168,180,189,192,195,200,210,216,225,231,240,243
%N A097752 Least integer with each "mod 4 prime signature".
%C A097752 See A097751 for definition of "mod 4 prime signature".
%C A097752 A097751 sorted and duplicates removed; n such that A097751(n)=n.
%H A097752 Charles R Greathouse IV, <a href="/A097752/b097752.txt">Table of n, a(n) for n = 1..10000</a>
%H A097752 Charles R Greathouse IV, <a href="/A097752/a097752.gp.txt">PARI/GP script to find terms of this sequence</a>
%t A097752 mod4PrimeSignature[n_] := {fi = FactorInteger[n]; If[OddQ[n], 0, fi[[1, 2]]], Select[fi, Mod[#[[1]], 4] == 3 &][[All, 2]]//Sort, Select[fi, Mod[#[[1]], 4] == 1 &][[All, 2]]}; A097751[n_] := Catch[For[k = 2, True, k++, If[ mod4PrimeSignature[k] == mod4PrimeSignature[n], Throw[k]]]]; A097751[1] = 1; Select[ Range[243], A097751[#] == # &] (* _Jean-François Alcover_, Jan 10 2013 *)
%o A097752 (PARI) is(n)=n>>=valuation(n,2); my(e3=valuation(n,3),e1=valuation(n,5),e); n/=3^e3 * 5^e1; forprime(p=7,, e=valuation(n,p); if(p%4==1, if(e1<e, return(0)); e1=e, if(e3<e, return(0)); e3=e); if(e, n/=p^e, if(e1==0 && e3==0, return(n==1)))) \\ _Charles R Greathouse IV_, Dec 10 2016
%o A097752 (PARI) See Greathouse link.
%Y A097752 Cf. A097751, A097753, A097754, A097755, A097756.
%K A097752 nonn
%O A097752 1,2
%A A097752 _Ray Chandler_, Aug 26 2004