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A027496 Cube of the lower triangular normalized 2nd kind Stirling matrix. 6
1, 7, 1, 379, 117, 4, 8887, 4297, 312, 4, 3634247, 2411993, 273657, 7418, 45, 512080090549, 435104283499, 67806664899, 2877230158, 36766575, 121680, 267019057484932787, 278169352029443501, 55479403017630012 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..24.

FORMULA

Numerators of lower triangle of (a[ i, j ])^3 where a[ i, j ] = S(i, j)/BellNumber(i) if j<=i, 0 if j>i

MATHEMATICA

rows = 7; m = Table[If[k <= n, StirlingS2[n, k]/BellB[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 *)

CROSSREFS

Cf. A008277.

Sequence in context: A027478 A009792 A103243 * A056009 A159252 A245329

Adjacent sequences:  A027493 A027494 A027495 * A027497 A027498 A027499

KEYWORD

nonn,tabl

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified April 7 04:20 EDT 2020. Contains 333292 sequences. (Running on oeis4.)