login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093618 Numbers n such that for all k less than n the number of divisors of k*n and n^2 are different. 3
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A093616(a(n)) = n; complement of A093617.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1800

MATHEMATICA

A093616[n_] := For[k = 1, True, k++, If[DivisorSigma[0, k*n] == DivisorSigma[0, n^2], Return[k]]]; Select[Range[100], A093616[#] == # &] (* Jean-Fran├žois Alcover, Aug 14 2014 *)

CROSSREFS

Cf. A000005, A000290, A048691.

Sequence in context: A090322 A076084 A151764 * A317257 A242031 A109427

Adjacent sequences:  A093615 A093616 A093617 * A093619 A093620 A093621

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Apr 06 2004

EXTENSIONS

Corrected by Franklin T. Adams-Watters, Dec 19 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 09:35 EDT 2019. Contains 322385 sequences. (Running on oeis4.)