A115268 Correlation triangle for floor((n+4)/4).
1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 3, 2, 2, 2, 3, 3, 3, 3, 2, 2, 4, 4, 4, 4, 4, 2, 2, 4, 5, 5, 5, 5, 4, 2, 3, 4, 6, 6, 8, 6, 6, 4, 3, 3, 5, 6, 7, 9, 9, 7, 6, 5, 3, 3, 6, 7, 8, 10, 12, 10, 8, 7, 6, 3, 3, 6, 8, 9, 11, 13, 13, 11, 9, 8, 6, 3, 4, 6, 9, 10, 14, 14, 16, 14, 14, 10, 9, 6, 4
Offset: 0
Examples
Triangle begins 1; 1,1; 1,2,1; 1,2,2,1; 2,2,3,2,2; 2,3,3,3,3,2; 2,4,4,4,4,4,2; 2,4,5,5,5,5,4,2; 3,4,6,6,8,6,6,4,3; 3,5,6,7,9,9,7,6,5,3; 3,6,7,8,10,12,10,8,7,6,3; 3,6,8,9,11,13,13,11,9,8,6,3;
Formula
G.f.: (1+x+x^2+x^3)(1+xy+x^2*y^2+x^3*y^3)/((1-x^4)^2*(1-x^4*y^4)^2*(1-x^2*y)); Number triangle T(n, k)=sum{j=0..n, [j<=k]*floor((k-j+4)/4)*[j<=n-k]*floor((n-k-j+4)/4)}.
Comments