2289169

Appears in sequences

• Crystal ball sequence for D_4 lattice.at n=27A007204
• Number of n X 5 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.at n=15A208115
• a(n) is the lesser coefficient of the pair (x, y) such that (x^2-y^2)/r, 2*x*y/r, (x^2+y^2)/r are the 2 legs and hypotenuse of the least Pythagorean triple having area A006991(n).at n=18A364109