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A027537
Square of the lower triangular normalized Eulerian number matrix.
5
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
1,2
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
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 *)
CROSSREFS
Cf. A008292.
Sequence in context: A247232 A147076 A372175 * A192721 A370949 A002380
KEYWORD
nonn,tabl
STATUS
approved