A120075 Row sums of triangle A120073 (denominator triangle for H atom spectrum).

4, 45, 176, 750, 1101, 4459, 6080, 13284, 16350, 46585, 33954, 109850, 92463, 142705, 198400, 432344, 255096, 761349, 500355, 824866, 925529, 2007555, 1044616, 2612500, 2158130, 3301641, 2848741

Offset

2,1

Links

G. C. Greubel, Table of n, a(n) for n = 2..1000

Formula

a(n) = Sum_{k=1..n-1} A120073(n,k), for n >= 2.

Mathematica

A120075[n_]:= Sum[Denominator[1/k^2 -1/n^2], {k, n-1}];
Table[A120075[n], {n, 2, 50}] (* G. C. Greubel, Apr 24 2023 *)

Prog

(Magma)
A120073:= func< n, k | Denominator(1/k^2 - 1/n^2) >;
[(&+[A120073(n, k): k in [1..n-1]]): n in [2..50]]; // G. C. Greubel, Apr 24 2023
(SageMath)
def A120073(n, k): return denominator(1/k^2 - 1/n^2)
[sum(A120073(n, k) for k in range(1, n)) for n in range(2, 51)] # G. C. Greubel, Apr 24 2023

Crossrefs

Cf. A120070, A120072, A120073, A120074, A120076, A120077.

Sequence in context: A369228 A070225 A132998 * A273832 A273848 A123650

Adjacent sequences: A120072 A120073 A120074 * A120076 A120077 A120078

Keyword

nonn,easy

Author

Wolfdieter Lang, Jul 20 2006

Status

approved