OFFSET
1,1
COMMENTS
Integers n that cannot be expressed as the product of two numbers of the form a + b*sqrt(-11), where a > 0 and b >= 0 (excluding 1 and n).
FORMULA
a(n) ~ 6/5 * n log n.
PROG
(Magma) Sort([11] cat [p: p in PrimesUpTo(317) | NormEquation(11, p) eq false]);
CROSSREFS
KEYWORD
nonn
AUTHOR
Arkadiusz Wesolowski, Jan 19 2017
STATUS
approved