|
|
A023201
|
|
Primes p such that p + 6 is also prime. (Lesser of a pair of sexy primes.)
|
|
116
|
|
|
5, 7, 11, 13, 17, 23, 31, 37, 41, 47, 53, 61, 67, 73, 83, 97, 101, 103, 107, 131, 151, 157, 167, 173, 191, 193, 223, 227, 233, 251, 257, 263, 271, 277, 307, 311, 331, 347, 353, 367, 373, 383, 433, 443, 457, 461, 503, 541, 557, 563, 571, 587, 593, 601, 607, 613, 641, 647
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
Eric Weisstein's World of Mathematics, Sexy Primes. [The definition in this webpage is unsatisfactory, because it defines a "sexy prime" as a pair of primes.- N. J. A. Sloane, Mar 07 2021].
|
|
FORMULA
|
|
|
MAPLE
|
option remember;
if n = 1 then
5;
else
for a from procname(n-1)+2 by 2 do
if isprime(a) and isprime(a+6) then
return a;
end if;
end do:
end if;
|
|
MATHEMATICA
|
Select[Prime[Range[120]], PrimeQ[#+6]&] (* Harvey P. Dale, Mar 20 2018 *)
|
|
PROG
|
(Magma) [n: n in [0..40000] | IsPrime(n) and IsPrime(n+6)] // Vincenzo Librandi, Aug 04 2010
(Haskell)
a023201 n = a023201_list !! (n-1)
a023201_list = filter ((== 1) . a010051 . (+ 6)) a000040_list
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|