2895146102domain: NAppears in sequencesa(n) = 6*a(n-2) - a(n-4).at n=26A006452a(n) = 6*a(n-1) - a(n-2), n >= 2, a(0)=1, a(1)=2.at n=13A038725a(2n) = A001653(n) (Numbers n such that 2*n^2 - 1 is a square), a(2n+1) = A038725(n+1).at n=25A117719a(n) = sqrt(A299921(n)).at n=38A301318