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 A144913 #17 Dec 26 2021 15:32:40
%S A144913 4,9,16,25,36,49,64,81,100,121,144,169,196,225,256,324,400,441,484,
%T A144913 576,625,676,729,784,900,1024,1089,1225,1296,1521,1600,1764,1936,2025,
%U A144913 2304,2401,2500,2704,2916,3025,3136,3600,3969,4096,4225,4356,4900,5184,5625
%N A144913 Integers which are the product of even powers of primes up to 13.
%H A144913 Charles R Greathouse IV, <a href="/A144913/b144913.txt">Table of n, a(n) for n = 1..10000</a>
%F A144913 a(n) = A080197(n+1)^2. - _Rémy Sigrist_, Sep 26 2020
%F A144913 Sum_{n>=1} 1/a(n) = -1 + Product_{primes p <= 13} p^2/(p^2-1) = 273347/442368. - _Amiram Eldar_, Oct 14 2020
%t A144913 Select[ Range[75]^2, (fi = FactorInteger[#]; Max[ fi[[All, 1]] ] <= 13 && And @@ EvenQ /@ fi[[All, 2]]) &] (* _Jean-François Alcover_, Oct 10 2012 *)
%t A144913 eppQ[n_]:=Module[{fi=FactorInteger[n]},Max[fi[[All,1]]]<=13&&AllTrue[ fi[[All,2]],EvenQ]]; Select[Range[6000],eppQ] (* _Harvey P. Dale_, Dec 26 2021 *)
%o A144913 (PARI) is(n)=if(issquare(n,&n), my(f=factor(n)[,1]); #f && f[#f]<14, 0) \\ _Charles R Greathouse IV_, Jun 17 2013
%Y A144913 Subsequence of A000290 and A080197.
%Y A144913 Cf. A001694.
%K A144913 easy,nice,nonn
%O A144913 1,1
%A A144913 _Reikku Kulon_, Sep 25 2008, Sep 26 2008