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 A027450 #13 May 06 2022 07:55:23
%S A027450 11,13,47,37,214,365,955,847,8372,7602,90510,83490,77484,144573,
%T A027450 2303301,2167165,38878840,36824788,34977228,33306468,731129880,
%U A027450 699259470,3350272926,3215969526,9276087128,8931886700,249757779700,241131522060,7225531873560
%N A027450 Third diagonal of A027446.
%F A027450 Numerators of sequence a[ n, n-2 ] in (a[ i, j ])^2 where a[ i, j ] = 1/i if j<=i, 0 if j>i.
%t A027450 rows = 31;
%t A027450 M = MatrixPower[Table[If[j <= i, 1/i, 0], {i, 1, rows}, {j, 1, rows}], 2];
%t A027450 T = Table[M[[n]]*LCM @@ Denominator[M[[n]]], {n, 1, rows}];
%t A027450 a[n_] := T[[n, n-2]];
%t A027450 Table[a[n], {n, 3, rows}] (* _Jean-François Alcover_, May 06 2022 *)
%Y A027450 Cf. A027446.
%K A027450 nonn
%O A027450 3,1
%A A027450 _Olivier Gérard_
%E A027450 More terms from _Sean A. Irvine_, Nov 04 2019