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 A206566 #7 Jul 12 2012 00:40:00 %S A206566 0,1,1,0,0,0,1,0,1,1,0,1,1,1,1,1,1,2,1,2,2,0,0,0,0,0,0,0,1,0,1,0,1,0, %T A206566 1,1,0,1,1,0,0,1,1,1,1,1,1,2,0,1,1,2,1,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0, %U A206566 1,1,2,1,2,1,2,1,2,2,0,1,1,1,1,2,2,1,1,2,2,2,2,1,1,2,1,2,2,3,1 %N A206566 Triangular array: T(i,j) = number of terms common to the binary expansions of i+1 and j, for j=1,2,3,...,i; i=1,2,3,... %C A206566 Row n consists of the first n terms of column n+1 of A206479, and (n-th row sum)=A115478(n+1). %e A206566 First ten rows: %e A206566 0 %e A206566 1 1 %e A206566 0 0 0 %e A206566 1 0 1 1 %e A206566 0 1 1 1 1 %e A206566 1 1 2 1 2 2 %e A206566 0 0 0 0 0 0 0 %e A206566 1 0 1 0 1 0 1 1 %e A206566 0 1 1 0 0 1 1 1 1 %e A206566 1 1 2 0 1 1 2 1 2 2 %t A206566 d[n_] := IntegerDigits[n, 2]; %t A206566 t[n_] := Reverse[Array[d, 120][[n]]] %t A206566 s[n_] := Position[t[n], 1] %t A206566 t[m_, n_] := Length[Intersection[s[m], s[n]]] %t A206566 TableForm[Table[t[m, n], {m, 1, 14}, %t A206566 {n, 1, 14}]] (* A206479 as a matrix *) %t A206566 Flatten[Table[t[i, n + 1 - i], {n, 1, 14}, %t A206566 {i, 1, n}]] (* A206479 as a sequence *) %t A206566 u = Table[t[n - 1, m], {n, 3, 16}, {m, 1, n - 2}]; %t A206566 TableForm[u] (* A206566 as a triangle *) %t A206566 Flatten[u] (* A206566 as a sequence *) %t A206566 v[n_] := Table[t[k, n + 1], {k, 1, n}] %t A206566 Table[Count[v[n], 0], {n, 1, 100}] (* A115478 *) %Y A206566 Cf. A206479, A115478. %K A206566 nonn,tabl,base %O A206566 1,18 %A A206566 _Clark Kimberling_, Feb 09 2012