4653525600domain: NAppears in sequencesa(n) = 4*(2n+1)!/n!^2.at n=14A002011a(n) = (n+1)*binomial(n+1, 15).at n=15A027775Sum of squared terms in rows of triangle A152547: a(n) = Sum_{k=0..C(n,[n/2])-1} A152547(n,k)^2.at n=29A152548a(0) = 1; for n >= 1, a(n) = A059897(n, a(n-1)).at n=29A284567