54009348606domain: NAppears in sequencesNumbers k such that 10*k^2 + 9 is a square.at n=21A075836a(n) = 6*a(n-2) + a(n-4), where a(0) = 3, a(1) = 11, a(2) = 18, a(3) = 68.at n=26A228470