The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A175779 Triangle T(n,m) read by rows: numerator of 1/(n-m)^2 - 1/n^2. 2

%I #10 Sep 20 2018 00:35:48

%S 1,0,1,0,3,1,0,5,8,1,0,7,3,15,1,0,9,16,21,24,1,0,11,5,1,2,35,1,0,13,

%T 24,33,40,45,48,1,0,15,7,39,3,55,15,63,1,0,17,32,5,56,65,8,77,80

%N Triangle T(n,m) read by rows: numerator of 1/(n-m)^2 - 1/n^2.

%C T(n,0) is set to zero at the pole m=0. T(n,n) is otherwise set to 1 at the pole n=m.

%C This is the triangle A061035 augmented by a diagonal of 1's.

%C Essentially the same information is in A120072, A166492, A172157 and A174233.

%H G. C. Greubel, <a href="/A175779/b175779.txt">Rows n=0..100 of triangle, flattened</a>

%e The triangle starts in row n=0 with columns 0<=m<=n as:

%e .1.

%e .0..1.

%e .0..3..1.

%e .0..5..8..1.

%e .0..7..3.15..1.

%e .0..9.16.21.24..1.

%e .0.11..5..1..2.35..1.

%e .0.13.24.33.40.45.48..1.

%e .0.15..7.39..3.55.15.63..1.

%e .0.17.32..5.56.65..8.77.80..1.

%e .0.19..9.51..4..3.21.91..6.99..1.

%t T[n_, n_] := 1; T[n_, k_] := 1/(n - k)^2 - 1/n^2; Table[Numerator[T[n, k]], {n, 0, 20}, {k, 0, n}] // Flatten (* _G. C. Greubel_, Sep 19 2018 *)

%Y Cf. A172157, A166925, A171522 (denominators)

%K nonn,frac,tabl

%O 0,5

%A _Paul Curtz_, Dec 04 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 19 00:35 EDT 2024. Contains 372666 sequences. (Running on oeis4.)