A093919 -id:A093919 - cp's OEIS frontend

A093920 Row sums of A093919.

1, 4, 15, 40, 205, 276, 1939, 4432, 13689, 18100, 199111, 200784, 2610205, 3136420, 3191595, 7012576, 119213809, 137103012, 2604957247, 2605199080, 2608367181, 3084857644, 70951725835, 71062911792, 355315542025, 442803520276

Offset: 1

Amarnath Murthy, Apr 25 2004

nonn

Cf. A093919.

T[n_, k_] := LCM @@ Drop[ Reverse[ Range[n]], (k - n)]; Table[ Plus @@ Table[ T[n, k], {k, n}], {n, 26}] (* Robert G. Wilson v, Apr 27 2004 *)

Edited by Robert G. Wilson v, Apr 27 2004

A179661 Triangle read by rows: T(n,k) is the largest least common multiple of any k-element subset of the first n positive integers.

Original entry on oeis.org

1, 2, 2, 3, 6, 6, 4, 12, 12, 12, 5, 20, 60, 60, 60, 6, 30, 60, 60, 60, 60, 7, 42, 210, 420, 420, 420, 420, 8, 56, 280, 840, 840, 840, 840, 840, 9, 72, 504, 2520, 2520, 2520, 2520, 2520, 2520, 10, 90, 630, 2520, 2520, 2520, 2520, 2520, 2520, 2520, 11, 110, 990

Offset: 1

Enrique Pérez Herrero, Jan 09 2011

Sequence differs from A093919; first divergences are at indices 31, 40, 48, 59.

Main diagonal is A003418.

			Triangle begins:
    [ 1 ],
    [ 2, 2 ],
    [ 3, 6, 6 ],
    [ 4, 12, 12, 12 ],
    [ 5, 20, 60, 60, 60 ],
    [ 6, 30, 60, 60, 60, 60 ].

Cf. A093919, A096179, A003418.

A179661:=func< n, k | Max([ LCM(s): s in Subsets({1..n}, k) ]) >; z:=12; [ A179661(n, k): k in [1..n], n in [1..z] ]; // Klaus Brockhaus, Jan 16 2011

A179661[n_,k_]:=Max[LCM@@@Subsets[Range[n],{k}]];
A002260[n_]:=n-Binomial[Floor[1/2+Sqrt[2*n]],2];
A002024[n_]:=Floor[1/2+Sqrt[2*n]];
A179661[n_]:=A179661[A002024[n],A002260[n]]

T(n,k) = max{ lcm(x_1,...,x_k) ; 0 < x_1 < ... < x_k <= n }.

cp's OEIS Frontend

A093920 Row sums of A093919.

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A179661 Triangle read by rows: T(n,k) is the largest least common multiple of any k-element subset of the first n positive integers.

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