OFFSET
1,1
LINKS
Marc Deléglise, Pierre Dusart, and Xavier-Francois Roblot, Counting primes in residue classes, Math. Comp. 73 (2004), no. 247, 1565-1575
Eric Weisstein's World of Mathematics, Gaussian Prime
FORMULA
a(n) ~ 4 Li(10^n) ~ k/n * 10^n, where k = 4/log(10) = 1.737.... - Charles R Greathouse IV, Oct 24 2012
MATHEMATICA
Table[lim2=10^n; lim1=Floor[Sqrt[lim2]]; cnt=0; Do[If[x^2+y^2<lim2&&PrimeQ[x+I y, GaussianIntegers->True], cnt++ ], {x, -lim1, lim1}, {y, -lim1, lim1}]; cnt, {n, 6}]
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Dec 19 2003
EXTENSIONS
a(10)-a(16) from Seiichi Manyama using the data in A091098, Dec 03 2017
STATUS
approved