login
A027518
4th power of the lower triangular normalized partition matrix.
6
1, 15, 1, 575, 65, 8, 28759, 4393, 544, 54, 26454859, 4978093, 871144, 95904, 13500, 35854425017, 7684637159, 1436323472, 190754352, 27540000, 3087000, 141598322427, 34558204013, 7383254904, 1130247120, 197499248, 24685024
OFFSET
1,2
FORMULA
Numerators of lower triangle of (a[i, j])^4 where a[i, j] = A008284(i, j) / Partitions(i) if j<=i, 0 if j>i.
MATHEMATICA
rows = 7; m = Table[If[k <= n, Length[IntegerPartitions[n, {k}]]/PartitionsP[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
Cf. A008284.
Sequence in context: A049224 A223517 A027448 * A027539 A027479 A027497
KEYWORD
nonn,tabl
STATUS
approved