81025domain: NAppears in sequencesa(1)=1, a(n) = a(n-1) + n^5 if n odd, a(n) = a(n-1) + n^3 if n is even.at n=9A1350991/4 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 25.at n=12A159225Second class of all proper positive solutions y2(n) = a(n) of the Pell equation x^2 - 7*y^2 = 9.at n=4A307173