OFFSET
1,1
COMMENTS
Sequence motivated by a comment in A024702: "The set of prime factors of a(n), however, appears to include all primes".
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1) = 7 because 7 is the least prime p such that (p^2-1)/24, which is 2, is divisible by 2=prime(1).
a(2) = 17 because 17 is the least prime p such that (p^2-1)/24, which is 12, is divisible by 3=prime(2).
a(3) = 11 because 11 is the least prime p such that (p^2-1)/24, which is 5, is divisible by 5=prime(3).
PROG
(PARI) a(n) = {p = prime(n); q = prime(3); while (! vecsearch(factor((q^2 - 1)/24)[, 1], p), q = nextprime(q+1)); q; }
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Sep 18 2016
STATUS
approved