cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A027538 Cube of the lower triangular normalized Eulerian number matrix.

Original entry on oeis.org

1, 7, 1, 163, 52, 1, 8873, 4719, 231, 1, 930581, 731646, 64966, 806, 1, 166430695, 180969681, 25235006, 610166, 2451, 1, 46667364787, 67248150516, 13560308427, 543687292, 4546137, 6840, 1, 19297882224241, 35761409868799, 9882496297869
Offset: 1

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Keywords

Crossrefs

Cf. A008292.

Programs

  • Mathematica
    rows = 8; 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}]; m3 = m.m.m; Table[fracs = m3[[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 ])^3 where a[ i, j ] = A(i, j)/i! if j<=i, 0 if j>i