The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A175116 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A175116

A positive integer k is included if d(k) = d(k+1) * d(k+2), where d(k) is the number of divisors of k.
(history; published version)

#15 by Alois P. Heinz at Wed Jul 17 07:36:37 EDT 2019

STATUS

proposed

approved

#14 by Amiram Eldar at Wed Jul 17 06:27:24 EDT 2019

STATUS

editing

proposed

#13 by Amiram Eldar at Wed Jul 17 06:09:16 EDT 2019

NAME

A positive integer n k is included if d(nk) = d(nk+1) * d(nk+2), where d(nk) is the number of divisors of nk.

LINKS

Amiram Eldar, <a href="/A175116/b175116.txt">Table of n, a(n) for n = 1..10000</a>

CROSSREFS

Cf. A000005, A175115, A145470.

STATUS

approved

editing

#12 by N. J. A. Sloane at Sat Apr 04 10:01:59 EDT 2015

COMMENTS

Terms calculated by _M. F. Hasler_.

Discussion

Sat Apr 04

10:01

OEIS Server: https://oeis.org/edit/global/2390

#11 by N. J. A. Sloane at Sat Apr 04 09:59:11 EDT 2015

COMMENTS

Terms calculated by Maximilian M. F. Hasler.

Discussion

Sat Apr 04

09:59

OEIS Server: https://oeis.org/edit/global/2388

#10 by Charles R Greathouse IV at Tue Mar 11 01:32:50 EDT 2014

AUTHOR

__Leroy Quet__, , Feb 13 2010

Discussion

Tue Mar 11

01:32

OEIS Server: https://oeis.org/edit/global/2122

#9 by N. J. A. Sloane at Wed Feb 05 20:19:00 EST 2014

AUTHOR

__Leroy Quet_, _, Feb 13 2010

Discussion

Wed Feb 05

20:19

OEIS Server: https://oeis.org/edit/global/2118

#8 by N. J. A. Sloane at Wed Feb 05 20:12:15 EST 2014

AUTHOR

_Leroy Quet, _, Feb 13 2010

Discussion

Wed Feb 05

20:12

OEIS Server: https://oeis.org/edit/global/2117

#7 by Charles R Greathouse IV at Thu Nov 21 12:50:01 EST 2013

MATHEMATICA

Transpose[Select[Partition[Range[3000], 3, 1], DivisorSigma[0, First[#]]== DivisorSigma[0, Last[#]]DivisorSigma[0, #[[2]]]&]][[1]] (* From _Harvey P. Dale, _, Apr 08 2011 *)

Discussion

Thu Nov 21

12:50

OEIS Server: https://oeis.org/edit/global/2062

#6 by N. J. A. Sloane at Sat Apr 09 00:09:30 EDT 2011

STATUS

reviewed

approved