|
|
A161504
|
|
Primes congruent to {1, 2, 10, 11, 19, 20} mod 21.
|
|
1
|
|
|
2, 11, 19, 23, 31, 41, 43, 53, 61, 73, 83, 103, 107, 127, 137, 149, 157, 167, 179, 191, 199, 211, 229, 233, 241, 251, 263, 271, 283, 293, 313, 317, 337, 347, 359, 367, 379, 389, 397, 401, 409, 419, 421, 431, 439, 443, 461, 463, 503, 523, 547, 557, 569, 577, 587
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
The cyclotomic polynomial Phi(21p,x) is flat only for p in this sequence.
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Flatten[Table[Select[21*n+{-10, -2, -1, 1, 2, 10}, PrimeQ], {n, 50}]]
Select[Prime[Range[2, 250]], MemberQ[{1, 2, 10, 11, 19, 20}, Mod[#, 21]]&] (* Harvey P. Dale, May 03 2019 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|