OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = sqrt(A110586(n)). - Amiram Eldar, Aug 02 2024
EXAMPLE
a(4) = 17 since 17^2 = 289 = 6*47 + 7.
MAPLE
ispower := proc(n, b) andmap(proc(w) evalb(w[2] mod b = 0) end, ifactors(n)[2]) end: a:=6: SQP||a:=[]: for z from 1 to 1 do for n from 1 to 1000 do p:=ithprime(n); m:=a*p+a+1; if ispower(m, 2) and isprime(sqrt(m)) then SQPW||a:=[op(SQP||a), sqrt(m)] fi od; od; SQP||a;
MATHEMATICA
Select[Prime[Range[135]], PrimeQ[(#^2-7)/6] &] (* Amiram Eldar, Aug 02 2024 *)
PROG
(PARI) is(p) = isprime(p) && !((p^2-7) % 6) && isprime((p^2-7)/6); \\ Amiram Eldar, Aug 02 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Walter Kehowski, Sep 13 2005
STATUS
approved