584104domain: NAppears in sequencesa(n) = (sum of first n primes)^2 - sum of squares of first n primes.at n=21A065595Number of Catalan knight paths from (0,0) to (n,3) in the region between and on the lines y=0 and y=3. (See A096587 for the definition of Catalan knight.).at n=25A099331