A181854 Triangle read by rows: Partial row sums of A181853(n,k)

1, 1, 2, 1, 4, 6, 1, 7, 18, 24, 1, 11, 42, 76, 88, 1, 16, 97, 286, 468, 528, 1, 22, 163, 556, 1050, 1332, 1392, 1, 29, 317, 1697, 4942, 8682, 10716, 11136, 1, 37, 493, 3209, 11502, 24770, 36108, 41016, 41856

Offset

0,3

Links

Alois P. Heinz, Rows n = 0..25, flattened

Example

[0]   1
[1]   1    2
[2]   1    4     6
[3]   1    7    18    24
[4]   1   11    42    76     88
[5]   1   16    97   286    468    528
[6]   1   22   163   556   1050   1332   1392

Maple

with(combstruct):
a181854_row := proc(n) local k, L, l, R, comb;
R := NULL; L := 0;
for k from 0 to n do
   comb := iterstructs(Combination(n), size=k):
   while not finished(comb) do
      l := nextstruct(comb);
      L := L + ilcm(op(l));
   od;
   R := R, L;
od;
R end:

Mathematica

t[_, 0] = 1; t[n_, k_] := Sum[LCM @@ c, {c, Subsets[Range[n], {k}]}]; row[n_] := Table[t[n, k], {k, 0, n}] // Accumulate; Table[row[n], {n, 0, 8}] // Flatten (* Jean-François Alcover, Jul 30 2013 *)

Crossrefs

Cf. A096179, A181853.

Sequence in context: A219441 A219142 A220226 * A109822 A274292 A359670

Adjacent sequences: A181851 A181852 A181853 * A181855 A181856 A181857

Keyword

nonn,tabl

Author

Peter Luschny, Dec 06 2010

Status

approved