OFFSET
1,1
COMMENTS
It appears that the generating function k*x^2-1 will produce all primes eventually with some repetitions.
If k>2 is a square, there is no entry corresponding to k*x^2-1. Bunyakovsky's conjecture implies that there are primes for all other k. - Robert Israel, Nov 22 2020
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
If p>=5 is prime, a(p+3-floor(sqrt(p)))=p. - Robert Israel, Nov 22 2020
MAPLE
f:= proc(k) local x;
if issqr(k) then return NULL fi;
for x from 1 do if isprime(k*x^2-1) then return k*x^2-1 fi od
end proc:
f(1):= 3: f(4):= 3:
map(f, [$1..300]); # Robert Israel, Nov 22 2020
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Dec 18 2003
STATUS
approved