This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A175779 #10 Sep 20 2018 00:35:48
%S A175779 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 A175779 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 A175779 Triangle T(n,m) read by rows: numerator of 1/(n-m)^2 - 1/n^2.
%C A175779 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 A175779 This is the triangle A061035 augmented by a diagonal of 1's.
%C A175779 Essentially the same information is in A120072, A166492, A172157 and A174233.
%H A175779 G. C. Greubel, <a href="/A175779/b175779.txt">Rows n=0..100 of triangle, flattened</a>
%e A175779 The triangle starts in row n=0 with columns 0<=m<=n as:
%e A175779 .1.
%e A175779 .0..1.
%e A175779 .0..3..1.
%e A175779 .0..5..8..1.
%e A175779 .0..7..3.15..1.
%e A175779 .0..9.16.21.24..1.
%e A175779 .0.11..5..1..2.35..1.
%e A175779 .0.13.24.33.40.45.48..1.
%e A175779 .0.15..7.39..3.55.15.63..1.
%e A175779 .0.17.32..5.56.65..8.77.80..1.
%e A175779 .0.19..9.51..4..3.21.91..6.99..1.
%t A175779 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 A175779 Cf. A172157, A166925, A171522 (denominators)
%K A175779 nonn,frac,tabl
%O A175779 0,5
%A A175779 _Paul Curtz_, Dec 04 2010