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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A227082 a(n) is the least positive integer not yet in the sequence coprime to a(d) for every proper divisor d of n. 2
1, 2, 3, 5, 4, 7, 6, 9, 8, 11, 10, 13, 12, 17, 19, 23, 14, 25, 15, 21, 29, 27, 16, 31, 33, 35, 37, 41, 18, 43, 20, 47, 49, 39, 53, 59, 22, 61, 55, 67, 24, 65, 26, 71, 73, 45, 28, 79, 77, 83, 85, 89, 30, 97, 51, 91, 32, 95, 34, 101, 36, 57, 103, 107, 109, 113, 38, 121, 115, 125, 40, 127, 42, 63, 119, 131, 133, 137, 44, 139, 143, 145, 46, 149 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is a permutation of the positive integers.

The subsequence (a(prime(i))) is strictly increasing.

a(i) < a(prime(j)) implies i < prime(j).

LINKS

Paul Tek, Table of n, a(n) for n = 1..10000

Paul Tek, PERL program for this sequence

EXAMPLE

a(1) = min { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... } = 1

a(2) = min {    2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... } = 2

a(3) = min {       3, 4, 5, 6, 7, 8, 9, 10, 11, ... } = 3

a(4) = min {             5,    7,    9,     11, ... } = 5

a(5) = min {          4,    6, 7, 8, 9, 10, 11, ... } = 4

a(6) = min {                   7,           11, ... } = 7

PROG

(Perl) See Tek link.

CROSSREFS

Cf. A227142.

Sequence in context: A098313 A098311 A230086 * A227142 A246696 A246698

Adjacent sequences:  A227079 A227080 A227081 * A227083 A227084 A227085

KEYWORD

nonn

AUTHOR

Paul Tek, Jun 30 2013

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 December 14 22:42 EST 2019. Contains 329987 sequences. (Running on oeis4.)