|
|
A083735
|
|
Pseudoprimes to bases 3 and 7.
|
|
3
|
|
|
703, 1105, 2465, 10585, 18721, 19345, 29341, 38503, 46657, 50881, 75361, 76627, 88831, 104653, 115921, 146611, 162401, 188191, 213265, 226801, 252601, 278545, 286903, 294409, 314821, 334153, 340561, 359341, 385003, 385201, 399001, 410041
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = n-th positive integer k(>1) such that 3^(k-1) = 1 (mod k) and 7^(k-1) = 1 (mod k).
|
|
EXAMPLE
|
a(1)=703 since it is the first number such that 3^(k-1) = 1 (mod k) and 7^(k-1) = 1 (mod k).
|
|
MATHEMATICA
|
Select[Range[420000], !PrimeQ[#]&&PowerMod[3, #-1, #]==1&&PowerMod[7, #-1, #] == 1&] (* Harvey P. Dale, Mar 08 2014 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Serhat Sevki Dincer (sevki(AT)ug.bilkent.edu.tr), May 05 2003
|
|
STATUS
|
approved
|
|
|
|