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 A331218 #12 Jan 14 2020 00:54:21 %S A331218 1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,2, %T A331218 1,0,1,0,1,0,1,0,1,0,3,0,1,0,1,0,1,0,1,0,1,4,1,0,1,0,1,0,1,0,1,0,5,0, %U A331218 1,0,1,0,1,0,1,0,1,6,1,0,1,0,1,0,1,0,1 %N A331218 a(n) is the numbers of ways to write n = u + v where the decimal representations of u and of v have the same number of digits d for d = 0..9. %C A331218 In other words, a(n) is the number of ways to write n as the sum of two anagrams. %C A331218 Leading zeros are ignored. %H A331218 Rémy Sigrist, <a href="/A331218/b331218.txt">Table of n, a(n) for n = 0..20000</a> %H A331218 Rémy Sigrist, <a href="/A331218/a331218.gp.txt">PARI program for A331218</a> %H A331218 Rémy Sigrist, <a href="/A331218/a331218.png">Scatterplot of (x, y) such that 0 <= x, y <= 10^3 and x and y are decimal anagrams</a> (a(n) corresponds to the number of pixels (x, y) such that x+y = n) %e A331218 For n = 44: %e A331218 - we have the following ways to write 44 as a sum of two anagrams: %e A331218 u v %e A331218 -- -- %e A331218 13 31 %e A331218 22 22 %e A331218 31 13 %e A331218 - hence a(44) = 3. %o A331218 (PARI) See Links section. %Y A331218 Cf. A330827 (ternary analog), A331216 (binary analog). %K A331218 nonn,base %O A331218 0,34 %A A331218 _Rémy Sigrist_, Jan 12 2020