A186641 - OEIS

A186641

Primes that are not cyclic numbers (A001913).

2, 3, 5, 11, 13, 31, 37, 41, 43, 53, 67, 71, 73, 79, 83, 89, 101, 103, 107, 127, 137, 139, 151, 157, 163, 173, 191, 197, 199, 211, 227, 239, 241, 251, 271, 277, 281, 283, 293, 307, 311, 317, 331, 347, 349, 353, 359, 373, 397, 401, 409, 421, 431, 439, 443, 449, 457, 463, 467, 479

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OFFSET

1,1

COMMENTS

Sequence A006559 with 2 and 5 included.

LINKS

Table of n, a(n) for n=1..60.

MAPLE

f1 := proc(n) local st, period:

st := ithprime(n):

period := numtheory[order](10, st):

if (st-1 <> period) then

RETURN(st):

fi: end: seq(f1(n), n=1..150);

PROG

(Python)

from itertools import islice

from sympy import nextprime, n_order

def A186641_gen(startvalue=1): # generator of terms >= startvalue

p = max(startvalue-1, 1)

while (p:=nextprime(p)):

if p==2 or p==5 or n_order(10, p)<p-1:

yield p

A186641_list = list(islice(A186641_gen(), 20)) # Chai Wah Wu, Mar 03 2025

CROSSREFS

Sequence in context: A277098 A096650 A111107 * A215354 A129201 A137692

Adjacent sequences: A186638 A186639 A186640 * A186642 A186643 A186644

KEYWORD

nonn

AUTHOR

Jani Melik, Feb 24 2011

STATUS

approved