OFFSET
1,2
FORMULA
Numerators of lower triangle of (a[ i, j ])^4 where a[ i, j ] = A(i, j)/i! if j<=i, 0 if j>i
MATHEMATICA
rows = 7; t[n_, k_] := Sum[(-1)^j*(k - j)^n*Binomial[n + 1, j], {j, 0, k}]; m = Table[If[k <= n, t[n, k]/n!, 0], {n, 1, rows}, {k, 1, rows}]; m4 = m.m.m.m; Table[fracs = m4[[i]]; nums = fracs // Numerator; dens = fracs // Denominator; lcm = LCM @@ dens; Table[ nums[[j]]*lcm/dens[[j]], {j, 1, i}], {i, 1, rows}] // Flatten (* Jean-François Alcover, Mar 05 2013 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
STATUS
approved