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 A165611 #9 Aug 27 2020 16:47:31 %S A165611 0,0,648,7128,85536,870750,8937054,89606088,899190558,8995054860, %T A165611 89990100090,899940633714,8999883000108,89999307063540, %U A165611 899998650010008,8999992080398088,89999984700000144,899999910900869040,8999999829000000162,89999999010004961988 %N A165611 The number of n-digit non-papaya numbers. %C A165611 These are numbers that are neither palindromes nor concatenations of two palindromes. Three digit numbers that are non-papaya are numbers with all distinct digits. There are 9*9*8 of them: 648. %H A165611 Tanya Khovanova, <a href="http://blog.tanyakhovanova.com/?p=177">Papaya Words and Numbers</a> %F A165611 a(n) = A052268(n) - A165135(n). %Y A165611 Cf. A165135, A165136, A165137, A165610. %K A165611 base,nonn %O A165611 1,3 %A A165611 _Tanya Khovanova_, Sep 22 2009 %E A165611 a(6)-a(20) from _Andrew Howroyd_, Mar 29 2016