login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A318261 a(n) is the odd part of A318262(n). 1
3, 3, 7, 5, 3, 7, 15, 5, 3, 7, 15, 31, 9, 5, 21, 3, 7, 15, 31, 63, 9, 21, 3, 7, 15, 31, 63, 127, 17, 9, 5, 21, 85, 3, 51, 7, 15, 31, 63, 127, 255, 17, 9, 73, 5, 21, 85, 3, 51, 7, 15, 31, 63, 127, 255, 511, 33, 17, 73, 5, 21, 85, 341, 11, 93, 3, 51, 7, 15, 31 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The odd part of n is the largest odd divisor of n (A000265).

LINKS

Peter Luschny, Table of n, a(n) for n = 1..1000

PROG

(Sage)

def A318261_list(len):

    count = 0; n = 0; L = []

    while count < len:

        n += 2

        m = power_mod(2, euler_phi(n), n)

        if m.is_power_of(2):

            v = 2^valuation(n, 2)

            L.append(n // v)

            count += 1

    return L

print(A318261_list(70))

CROSSREFS

Cf. A000265, A318262.

Sequence in context: A324573 A096633 A175482 * A118362 A258273 A205680

Adjacent sequences:  A318258 A318259 A318260 * A318262 A318263 A318264

KEYWORD

nonn

AUTHOR

Peter Luschny, Sep 05 2018

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 March 30 19:49 EDT 2020. Contains 333127 sequences. (Running on oeis4.)