A027458 Third column of A027446.

2, 7, 47, 57, 459, 1023, 3349, 3601, 42131, 44441, 605453, 631193, 655217, 1355479, 23763863, 24444543, 476698557, 488338185, 499423545, 510005025, 11962908135, 12186001005, 62000850801, 63030510201, 192066102203, 194934439103, 5733412167187, 5811048485947

Offset: 3

Author

Olivier Gérard

Keywords

• nonn

Programs

Mathematica

rows = 30;
M = MatrixPower[Table[If[j <= i, 1/i, 0], {i, 1, rows}, {j, 1, rows}], 2];
T = Table[M[[n]]*LCM @@ Denominator[M[[n]]], {n, 1, rows}];
a[n_] := T[[n, 3]];
Table[a[n], {n, 3, rows}] (* Jean-François Alcover, May 06 2022 *)

Formula

Numerators of sequence a[ 3, n ] in (a[ i, j ])^2 where a[ i, j ] = 1/i if j<=i, 0 if j>i

Extensions

More terms from Sean A. Irvine, Nov 04 2019