The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A027449 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A027449

Second diagonal of A027446.
(history; published version)

#13 by Peter Luschny at Fri May 06 07:55:33 EDT 2022

STATUS

reviewed

approved

#12 by Michel Marcus at Fri May 06 07:47:34 EDT 2022

STATUS

proposed

reviewed

#11 by Jean-François Alcover at Fri May 06 05:12:20 EDT 2022

STATUS

editing

proposed

#10 by Jean-François Alcover at Fri May 06 05:12:15 EDT 2022

MATHEMATICA

rows = 31;

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, n-1]];

Table[a[n], {n, 2, rows}] (* Jean-François Alcover, May 06 2022 *)

STATUS

approved

editing

#9 by Alois P. Heinz at Mon Nov 04 19:34:40 EST 2019

STATUS

editing

approved

#8 by Alois P. Heinz at Mon Nov 04 19:34:34 EST 2019

FORMULA

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

CROSSREFS

Cf. A027446.

STATUS

proposed

editing

#7 by Sean A. Irvine at Mon Nov 04 19:27:37 EST 2019

STATUS

editing

proposed

#6 by Sean A. Irvine at Mon Nov 04 19:27:27 EST 2019

DATA

3, 5, 7, 27, 22, 130, 225, 595, 532, 5292, 4830, 57750, 53460, 49764, 93093, 1486485, 1401400, 25185160, 23891868, 22724988, 21666840, 476166600, 455885430, 2186310126, 2100505176, 6063549800, 5842908500, 163495203300, 157949751960, 4735815444360

EXTENSIONS

More terms from Sean A. Irvine, Nov 04 2019

STATUS

approved

editing

#5 by Russ Cox at Fri Mar 30 17:20:43 EDT 2012

AUTHOR

Olivier Gerard (olivier.gerard(AT)gmail.com)

Olivier Gérard

Discussion

Fri Mar 30

17:20

OEIS Server: https://oeis.org/edit/global/117

#4 by N. J. A. Sloane at Fri Jan 09 03:00:00 EST 2009

KEYWORD

nonn,new

nonn

AUTHOR

Olivier Gerard (ogerardolivier.gerard(AT)ext.jussieugmail.frcom)