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 A046393 #15 Oct 10 2019 22:47:12 %S A046393 66,222,282,434,474,494,555,595,606,646,777,969,1001,1221,1551,1771, %T A046393 2222,2882,3333,3553,4334,4994,5335,5555,5665,5885,5995,6226,6446, %U A046393 6886,7337,7557,7667,7777,7887,8338,8558,8998,9339,9669,9779,9889,11211 %N A046393 Palindromes with exactly 3 distinct prime factors. %C A046393 The terms must have only three distinct prime factors even when counted with multiplicity. For example, 252 is not a term even though (1) it is a palindrome and (2) only three distinct primes occur when it is factored, because 252 = 2*2*3*3*7. - _Harvey P. Dale_, Aug 29 2016 %H A046393 Chai Wah Wu, <a href="/A046393/b046393.txt">Table of n, a(n) for n = 1..10000</a> %t A046393 Select[Range[12000],#==IntegerReverse[#]&&PrimeNu[#]==PrimeOmega[#]==3&] (* _Harvey P. Dale_, Aug 29 2016 *) %Y A046393 Cf. A046329, A046409. %K A046393 nonn,base %O A046393 1,1 %A A046393 _Patrick De Geest_, Jun 15 1998