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 A180925 #6 Feb 18 2019 04:56:26 %S A180925 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26, %T A180925 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,49,50, %U A180925 51,52,53,54,55,56,57,58,59,61,62,63,64,65,66,67,68,69,70 %N A180925 Natural numbers with palindromic number of divisors. %C A180925 The first natural number not in this sequence is 48, which has 10 divisors. The complement of this sequence begins 48, 60, 72, 80, 84, 90, 96, 108, 112, 120, 126, 132, 140, 144, 150, 156, 160, 162, 168, 176, 180, 192, 198, 200, ... - _Nathaniel Johnston_, May 27 2011 %H A180925 Nathaniel Johnston, <a href="/A180925/b180925.txt">Table of n, a(n) for n = 1..10000</a> %p A180925 read(transforms): with(numtheory): A180925 := proc(n) option remember: local k,t: if(n=1)then return 1: fi: for k from procname(n-1)+1 do t:=tau(k): if(t=digrev(t))then return k: fi: od: end: seq(A180925(n),n=1..100); # _Nathaniel Johnston_, May 27 2011 %Y A180925 Cf. A000005, A002113. %K A180925 base,easy,nonn %O A180925 1,2 %A A180925 _Giovanni Teofilatto_, Sep 25 2010