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A181843
Triangle read by rows: Partial row sums of A181842
3
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
1,3
EXAMPLE
[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
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 *)
CROSSREFS
Sequence in context: A049324 A356444 A256095 * A131111 A336574 A128549
KEYWORD
nonn,tabl
AUTHOR
Peter Luschny, Dec 07 2010
EXTENSIONS
Terms from an erroneous copy and paste transfer corrected.
More terms from Jean-François Alcover, Jul 26 2013
STATUS
approved