OFFSET
1,1
EXAMPLE
a(1) = 6 because there are 6 primes of the form b^2 + b + 1 for b <= 10: 3, 7, 13, 31, 43 and 73.
PROG
(PARI) {a(n) = sum(k=0, 10^n, isprime(k^2+k+1))}
(Python)
from sympy import isprime
def A319228(n):
c, b, b2, n10 = 0, 1, 3, 10**n
while b <= n10:
if isprime(b2):
c += 1
b += 1
b2 += 2*b
return c # Chai Wah Wu, Sep 17 2018
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Seiichi Manyama, Sep 14 2018
EXTENSIONS
a(10) from Chai Wah Wu, Sep 17 2018
a(11) from Chai Wah Wu, Sep 18 2018
STATUS
approved