1434840domain: NAppears in sequencesCentral terms of triangle A124328; a(n) = A124328(2n+1,n+1) for n>=0.at n=9A124889Number of planar triangular n X n X n nonnegative integer grids with mirror symmetry about one altitude with every similarly oriented 5 X 5 X 5 subtriangle summing to 15.at n=3A154094