A027537 Square of the lower triangular normalized Eulerian number matrix.

1, 3, 1, 19, 16, 1, 201, 319, 55, 1, 3131, 8296, 2816, 156, 1, 66883, 274089, 158774, 18254, 399, 1, 1866103, 11233692, 10137723, 2064028, 99093, 960, 1, 65599089, 559402687, 738815949, 240080355, 21320275, 481821, 2223, 1, 2826880471

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• tabl

Crossrefs

Cf. A008292.

Programs

Mathematica

rows = 9; 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}]; m2 = m.m; Table[fracs = m2[[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 *)

Formula

Numerators of lower triangle of (a[ i, j ])^2 where a[ i, j ] = A(i, j)/i! if j<=i, 0 if j>i