A120079 Unsigned row sums of triangle A120078.

1, 7, 68, 279, 7056, 7100, 349200, 1400175, 12622400, 12637296, 1530446400, 1531460700, 258950260800, 259056111600, 259141506624, 1036845584775, 299715332716800, 299771444772800, 108234634597689600, 108249271042728816, 108261866776377600, 108272784263716800

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Formula

a(n) = Sum_{k=1..n} abs(A120078(n,k)), n >= 1.

From G. C. Greubel, Apr 26 2023: (Start)

a(n) = (2 - 1/n^2)*A051418(n).

a(n) = A056220(n)*A051418(n)/A000290(n). (End)

Mathematica

Table[(2-1/n^2)*(Apply[LCM, Range[n]])^2, {n, 40}] (* G. C. Greubel, Apr 26 2023 *)

Prog

(Magma) [(2-1/n^2)*(Lcm([1..n]))^2: n in [1..40]]; // G. C. Greubel, Apr 26 2023
(SageMath)
def A120079(n): return (2 - 1/n^2)*(lcm(range(1, n+1)))^2
[A120079(n) for n in range(1, 41)] # G. C. Greubel, Apr 26 2023

Crossrefs

Signed row sums conjectured to be A027451(n), which also appears in the denominator of o.g.f.s. G(x, n) given in A120078 as numbers A(n).

Cf. A000290, A051418, A056220.

Sequence in context: A182127 A093170 A294664 * A297502 A087567 A328046

Adjacent sequences: A120076 A120077 A120078 * A120080 A120081 A120082

Keyword

nonn,easy

Author

Wolfdieter Lang, Jul 20 2006

Extensions

Terms a(11) onward added by G. C. Greubel, Apr 26 2023

Status

approved