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A105286
Numbers k such that prime(k+1) == 1 (mod k).
8
1, 2, 3, 10, 24, 25, 66, 168, 182, 186, 187, 188, 438, 6462, 40071, 40084, 40085, 40091, 40108, 40118, 251745, 637224, 637306, 637336, 637338, 10553441, 10553445, 10553452, 10553479, 10553515, 10553550, 10553829, 27067032, 27067054, 27067134, 69709710, 69709713, 179992838, 179993008, 3140421868, 8179002150, 55762149074, 1003652347080, 1003652347109, 1003652347112, 1003652347352, 1003652347375
OFFSET
1,2
COMMENTS
If k is a term, then prime(k+1)^prime(k+1) is a reverse Meertens number in base prime(k+1)^((prime(k+1)-1)/k). - Chai Wah Wu, Dec 14 2022
Integers k such that A004649(k+1) = 1. - Michel Marcus, Dec 30 2022
LINKS
Chai Wah Wu, Meertens Number and Its Variations, arXiv:1603.08493 [math.NT], 2016.
Chai Wah Wu, Meertens number and its variations, Communications on Number Theory and Combinatorial Theory, 3 (2022), article 5.
MATHEMATICA
bb={}; Do[If[1==Mod[Prime[n+1], n], bb=Append[bb, n]], {n, 1, 200000}]; bb
PROG
(Sage)
def A105286(max) :
terms = []
p = 3
for n in range(1, max+1) :
if (p - 1) % n == 0 : terms.append(n)
p = next_prime(p)
return terms
# Eric M. Schmidt, Feb 05 2013
(Python)
from itertools import count, islice
from sympy import prime
def A105286_gen(startvalue=1): # generator of terms >= startvalue
return filter(lambda k: not (prime(k+1)-1)%k, count(max(startvalue, 1)))
A105286_list = list(islice(A105286_gen(), 10)) # Chai Wah Wu, Dec 14 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Apr 25 2005
EXTENSIONS
More terms from Farideh Firoozbakht, May 12 2005
First term inserted by Eric M. Schmidt, Feb 05 2013
More terms from Michel Marcus, Dec 29 2022
a(40)-a(47) from Max Alekseyev, Aug 31 2024
STATUS
approved