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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A296243 Numbers n such that the multiplicative order of 2 modulo n is even. 3
3, 5, 9, 11, 13, 15, 17, 19, 21, 25, 27, 29, 33, 35, 37, 39, 41, 43, 45, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 75, 77, 81, 83, 85, 87, 91, 93, 95, 97, 99, 101, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 153 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Odd numbers n such that A007733(n) = A002326((n-1)/2) is even.

LINKS

Table of n, a(n) for n=1..64.

MATHEMATICA

A036259 = Select[Range[1, 199, 2], OddQ[MultiplicativeOrder[2, #]] &];

Range[1, A036259[[-1]], 2] ~Complement~ A036259 (* Jean-Fran├žois Alcover, Dec 20 2017 *)

PROG

(PARI) { is_A296243(n) = (n%2) && !(znorder(Mod(2, n))%2); }

CROSSREFS

Set difference of A005408 and A036259.

Contains A296244 as a subsequence.

The prime terms are given by A014662.

Sequence in context: A304251 A309135 A088607 * A162699 A325129 A173263

Adjacent sequences:  A296240 A296241 A296242 * A296244 A296245 A296246

KEYWORD

nonn

AUTHOR

Max Alekseyev, Dec 09 2017

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 October 16 09:29 EDT 2019. Contains 328056 sequences. (Running on oeis4.)