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!)
A176262 Numbers of the form 3k+1 with greatest prime divisor of the form 3m-1. 4
4, 10, 16, 22, 25, 34, 40, 46, 55, 58, 64, 82, 85, 88, 94, 100, 106, 115, 118, 121, 136, 142, 145, 154, 160, 166, 178, 184, 187, 202, 205, 214, 220, 226, 232, 235, 238, 250, 253, 256, 262, 265, 274, 289, 295, 298, 319, 322, 328, 334, 340, 346, 352, 355, 358, 376 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All numbers of the form 2p, where p==2(mod 3) is prime, are in the sequence.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[3 Range@ 120 + 1, Mod[#, 3] == 2 &[FactorInteger[#][[-1, 1]]] &] (* Michael De Vlieger, Feb 07 2016 *)

PROG

PARI) isok(n) = ((n % 3) == 1) && (n != 1) && ((vecmax(factor(n)[, 1]) % 3) == 2); \\ Michel Marcus, Feb 07 2016

CROSSREFS

Cf. A176258, A176257, A176256, A176255, A002148, A002145, A016813, A004767.

Sequence in context: A310515 A310516 A291745 * A310517 A310518 A310519

Adjacent sequences:  A176259 A176260 A176261 * A176263 A176264 A176265

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Apr 13 2010

EXTENSIONS

Corrected and extended by Michel Marcus, Feb 07 2016

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 July 6 08:51 EDT 2020. Contains 335476 sequences. (Running on oeis4.)