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 A075809 #11 Jan 05 2025 23:40:44 %S A075809 2,66,222,282,434,474,494,606,646,2222,2882,4334,4994,6006,6226,6446, %T A075809 6886,8338,8558,8778,8998,20002,20202,20702,20802,20902,22222,22922, %U A075809 24042,24342,24542,24742,24942,26062,26162,26462,28082,28182,28282 %N A075809 Palindromic even numbers with an odd number of distinct prime factors. %H A075809 Robert Israel, <a href="/A075809/b075809.txt">Table of n, a(n) for n = 1..10000</a> %e A075809 66=2*3*11, 222=2*3*37 and 282=2*3*47 are palindromic, even and products of an odd number of distinct primes. %p A075809 test := proc(n) local d; d := convert(n,base,10); return ListTools[Reverse](d)=d and numtheory[mobius](n)=-1; end; a := []; for n from 2 to 30000 by 2 do if test(n) then a := [op(a),n]; end; od; a; %Y A075809 Cf. A053858. %K A075809 nonn,base,look %O A075809 1,1 %A A075809 _Jani Melik_, Oct 13 2002 %E A075809 Edited by _Dean Hickerson_, Oct 21 2002