|
|
A111223
|
|
Numbers n such that 5*n + 2 is prime.
|
|
6
|
|
|
0, 1, 3, 7, 9, 13, 19, 21, 25, 27, 31, 33, 39, 45, 51, 55, 61, 63, 67, 69, 73, 79, 91, 93, 97, 109, 111, 115, 117, 121, 123, 129, 135, 145, 151, 157, 159, 165, 171, 175, 177, 181, 187, 189, 193, 195, 199, 217, 219, 223, 237, 243, 247, 255, 259, 261, 265, 273, 285
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
REFERENCES
|
T. Koshy, Fibonacci and Lucas Numbers with Applications, John Wiley, New York, 2001, p. 410 (Theorem 34.8).
|
|
LINKS
|
|
|
FORMULA
|
a(n) = F(p-2)/5 mod p, where p is the n-th prime number such that p==2 (mod 5) and F(m) is m-th Fibonacci number. - Rigoberto Florez, Mar 02 2020
|
|
EXAMPLE
|
97 is in the sequence because 5*97 + 2 = 487 is prime.
|
|
MATHEMATICA
|
Table[If[PrimeQ[5p+2], Mod[5^(-1) Fibonacci[5p], 5p+2], Unevaluated[Sequence[]]], {p, 0, 250}] (* Rigoberto Florez, Mar 02 2020 *)
Select[(#-2)/5&/@Prime[Range[250]], IntegerQ] (* Harvey P. Dale, Sep 27 2023 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|