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 A169618 #2 Mar 30 2012 17:35:24 %S A169618 1,2,2,3,3,3,6,6,2,2,5,5,5,5,5,6,6,6,6,6,6,7,11,8,12,2,6,3,12,20,4,4, %T A169618 12,4,4,4,15,15,6,6,6,6,6,6,15,10,10,10,10,10,10,10,10,10,10,11,11,11, %U A169618 11,11,11,11,11,11,11,11,18,18,6,6,18,18,6,6,18,18,6,6,13,11,18,8,20,15,6 %N A169618 Table with T(n,k) = the number of ways to represent k as the sum of a square and a cube modulo n. %C A169618 The top left corner is T(1,0). %C A169618 It appears that this table does not contain any 0's. %C A169618 It appears that row n is constant iff n is squarefree, and no prime divisor of n is == 1 (mod 6). It is not hard to show that such rows are constant, since the cubes are equi-distributed in such moduli. %e A169618 The 6 ways to represent 0 (mod 4) are 0^2+0^3, 0^2+2^3, 1^2+3^3, 2^2+0^3, 2^2+2^3, and 3^2+3^3. %o A169618 (PARI) al(n)=local(v);v=vector(n);for(i=0,n-1,for(j=0,n-1,v[(i^2+j^3)%n+1]++));v %Y A169618 Cf. A022549, A002476, A045309. %K A169618 nonn,tabl %O A169618 1,2 %A A169618 _Franklin T. Adams-Watters_, Dec 03 2009