a(m,n) tabl head (triangle) for A120070 (used for frequencies, energies, wave lengths of H-Atom spectrum) m\n 1 2 3 4 5 6 7 8 9 10 ... 2 3 0 0 0 0 0 0 0 0 0 3 8 5 0 0 0 0 0 0 0 0 4 15 12 7 0 0 0 0 0 0 0 5 24 21 16 9 0 0 0 0 0 0 6 35 32 27 20 11 0 0 0 0 0 7 48 45 40 33 24 13 0 0 0 0 8 63 60 55 48 39 28 15 0 0 0 9 80 77 72 65 56 45 32 17 0 0 10 99 96 91 84 75 64 51 36 19 0 11 120 117 112 105 96 85 72 57 40 21 . . . The generating functon for the column n numbers is A(n,x):=sum(a(m,n)*x^m,m=1..n-1) = (x^(n+1))*((2*n+1)- (2*n-1)*x)/(1-x)^3. Remark: In the calculation of these o.g.f.s one encounters the row polynomials of triangle A094728: G(n,x):= sum(a(m,n)*x^m,m=n+1..infty) = sum(a(m,n)*x^m,m=0..infty) - sum(a(m,n)*x^m,m=0..n) = (x d_x)^2 (1/(1-x)) - (n^2)/(1-x) + T(n,x), with T(n,x) the polynomial of row n of triangle A094728(n,k). E.g.: n=3: G(3,x) = (19*x-8*x^2-9)/(1-x)^3 + T(3,x) = (19*x-8*x^2-9)/(1-x)^3 + (9 + 8*x +5*x^2) = (x^4)*(7-5*x)/(1-x)^3. ################################################################################################### The generating function for the row sums [3, 13, 34, 70, 125, 203, 308, 444, 615, 825, ...] = A016061(n-1),n>=2, is x^2*(3+x)/(1-x)^4. ################################################################################################################### The rationals r(m,n):= a(m,n)/(m^2*n^2) are found under A120072 (numerators) and A120073 (denominators): See also the W. Lang link under A120072 for the r(m,n) table and the column o.g.f.s. There also the frequencies, energies and wave lengths of the H-spectrum series for n=1 (Lyman), n=2 (Balmer), n=3 (Paschen), n=4 (Brackett) and n=5 (Pfund) series are given. ############################################### e.o.f.##############################################################