A181843 Triangle read by rows: Partial row sums of A181842.

1, 1, 3, 1, 3, 6, 1, 3, 8, 12, 1, 3, 8, 18, 23, 1, 3, 8, 20, 32, 38, 1, 3, 8, 20, 38, 66, 73, 1, 3, 8, 20, 40, 78, 110, 118, 1, 3, 8, 20, 40, 84, 141, 189, 198, 1, 3, 8, 20, 40, 86, 153, 253, 308, 318, 1, 3, 8, 20, 40, 86, 159, 287, 409, 519, 530, 1, 3, 8, 20, 40, 86, 161, 299, 476, 728, 807, 819

Offset: 1

Author

Peter Luschny, Dec 07 2010

Keywords

• nonn
• tabl

Examples

			[1]   1
[2]   1   3
[3]   1   3   6
[4]   1   3   8   12
[5]   1   3   8   18   23
[6]   1   3   8   20   32   38
[7]   1   3   8   20   38   66   73
		

Crossrefs

Cf. A181842, A181844.

Programs

Maple

with(combstruct):
a181843_row := proc(n) local k,L,l,R,part;
R := NULL; L := 0;
for k from 1 to n do
   part := iterstructs(Partition(n),size=n-k+1):
   while not finished(part) do
      l := nextstruct(part);
      L := L + ilcm(op(l));
   od;
   R := R,L;
od;
R end:

Mathematica

t[n_, k_] := LCM @@@ IntegerPartitions[n, {n - k + 1}] // Total; row[n_] := Table[t[n, k], {k, 1, n}] // Accumulate; Table[row[n], {n, 1, 12}] // Flatten (* Jean-François Alcover, Jul 26 2013 *)

Extensions

Terms from an erroneous copy and paste transfer corrected.

More terms from Jean-François Alcover, Jul 26 2013