132840domain: NAppears in sequencesa(n) = n*(n+1)*(5*n^2 - n - 3)/2.at n=15A172118Area of the unique primitive Pythagorean triple (x,y,z) such that (x-y+z)/2 is A002315(n) and such that its long leg and its hypotenuse are consecutive natural numbers.at n=2A378966