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 A068893 #17 Dec 30 2020 04:11:56 %S A068893 13,15,17,26,31,37,39,51,58,62,71,73,79,85,93,97,107,113,115,117,122, %T A068893 123,129,143,149,155,157,158,159,165,167,169,177,178,179,183,185,187, %U A068893 199,203,205,221,226,246,265,285,286,294,302,311,314,319,321,326,327 %N A068893 Nonpalindromic numbers that have the same prime signature as their digit reversal. %H A068893 Amiram Eldar, <a href="/A068893/b068893.txt">Table of n, a(n) for n = 1..10000</a> %H A068893 <a href="/index/Pri#prime_signature">Index entries for sequences related to prime signature</a> %e A068893 15 is a term since 15 = 3*5 and 51 = 3*17, and both are of the form p*q where p and q are primes. %t A068893 sig[n_] := Sort @ FactorInteger[n][[;;,2]]; Select[Range[300], !PalindromeQ[#] && sig[#] == sig[IntegerReverse[#]] &] (* _Amiram Eldar_, Dec 30 2020 *) %Y A068893 Subsequence of A085869. %Y A068893 Cf. A004086, A118914. %K A068893 base,easy,nonn %O A068893 1,1 %A A068893 _Amarnath Murthy_, Mar 20 2002 %E A068893 More terms from _David Wasserman_, Apr 19 2005 %E A068893 Offset corrected by _Amiram Eldar_, Dec 30 2020