A094308 Row sums of A094307.

1, 3, 11, 34, 182, 282, 2034, 4908, 15564, 20100, 223620, 251340, 3295140, 3964380, 4324740, 9370200, 160014120, 180434520, 3440508120, 3673300680, 3906093240, 4350515400, 100294646760, 105648875640, 533598607080, 585081577080

Offset: 1

Author

Amarnath Murthy, Apr 29 2004

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..700

Crossrefs

Cf. A094307, A003418.

Lower diagonal of A181853. - Alois P. Heinz, Jul 29 2013

Programs

Maple

A094307 := proc(n,k) local a,i ; if n = 1 then RETURN(1) ; elif k > 1 and k < n then a := [seq(i,i=1..k-1),seq(i,i=k+1..n)] ; elif k = n then a := [seq(i,i=1..k-1)] ; else a := [seq(i,i=2..n)] ; fi ; ilcm(op(a)) ; end: A094308 := proc(n) local k ; add( A094307(n,k),k=1..n) ; end: for n from 1 to 40 do printf("%d, ",A094308(n)) ; od ; # R. J. Mathar, Apr 30 2007

Mathematica

T[n_, k_] := LCM @@ Which[n == 1, {1}, 1 < k < n, Join[Range[k - 1], Range[k + 1, n]], k == n, Range[k - 1], True, Range[2, n]];
a[n_] := Sum[T[n, k], {k, 1, n}];
Array[a, 30] (* Jean-François Alcover, May 20 2020 *)

PARI

T(n, k) = lcm(setminus(vector(n, i, i), Set(k))); \\ A094307
a(n) = sum(k=1, n, T(n,k)); \\ Michel Marcus, May 20 2020

Formula

a(n) = A003418(n) * (n - Sum_{frac(log_p(n)) < log_p(2)} (1 - 1/p)). - Charlie Neder, Jun 13 2019

Extensions

More terms from R. J. Mathar, Apr 30 2007