login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A167409 Very Orderly Numbers: a number, N, is "very orderly" if the set of the divisors of N is congruent to the set {1,2,...,tau(N)} mod tau(N)+1. 6
1, 2, 5, 8, 11, 12, 17, 20, 23, 27, 29, 38, 41, 47, 52, 53, 57, 58, 59, 68, 71, 72, 76, 83, 87, 89, 101, 107, 113, 117, 118, 124, 131, 133, 137, 149, 158, 162, 164, 167, 173, 177, 178, 179, 188, 191, 197, 203, 218, 227, 233, 236, 237, 239, 243, 244, 247, 251, 257 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The very orderly numbers are orderly numbers (Cf. A167408) with K = tau(N)+1

LINKS

A. Weimholt, Table of n, a(n) for n=1..10000

MATHEMATICA

veryOrderlyQ[n_] := (If[tau = DivisorSigma[0, n]; Union[Mod[Divisors[n], tau + 1]] == Range[tau], Return[True]]; False); Select[ Range[260], veryOrderlyQ] (* Jean-François Alcover, Aug 19 2013 *)

PROG

(PARI)

vo(n)=#(n=divisors(n))==#(n=Set(n%(1+#n))) & n[1]!="0"

for(n=1, 999, vo(n)&print1(n", ")) \\ M. F. Hasler

CROSSREFS

Cf. A167408 - Orderly Numbers

Cf. A167410 - Disorderly Numbers - numbers not in A167408

Cf. A167411 - Minimal K Values for the Orderly Numbers

Sequence in context: A177966 A083422 A187581 * A082406 A215938 A352748

Adjacent sequences: A167406 A167407 A167408 * A167410 A167411 A167412

KEYWORD

nonn

AUTHOR

Andrew Weimholt, Nov 03 2009

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 4 10:32 EST 2022. Contains 358556 sequences. (Running on oeis4.)