3051741058

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2), with a(0) = 0, a(1) = 2.at n=17A052530
• Limit of the sequence obtained from S(0) = (1,1) and, for n > 0, S(n) = I(S(n-1)), where I consists of inserting, for i = 1, 2, 3..., the term a(i) + a(i+1) between any two terms for which 7*a(i+1) <= 11*a(i).at n=33A082630
• The pairs (x,y) such that (x^2 + y^2)/(x*y + 1) is a perfect square, i.e., 4.at n=33A162959
• The pairs (x,y) such that (x^2 + y^2)/(x*y + 1) is a perfect square, i.e., 4.at n=34A162959