64107domain: NAppears in sequencesa(n) = b(n) + d(n), where b(n) = (n-th Lucas number > 3) and d(n) = (n-th non-Fibonacci number).at n=20A023487a(n) = b(n) + d(n), where b(n) = (n-th Lucas number > 1) and d(n) = (n-th non-Lucas number).at n=21A023493Numbers k such that k^2 is a 17-gonal number.at n=3A137879