The OEIS is supported by the many generous donors to the OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A091101 Number of first-quadrant Gaussian primes whose norm is less than 10^n. 2

%I #15 Feb 28 2020 04:32:25

%S 5,27,173,1245,9635,78525,664811,5762247,50850399,455056167

%N Number of first-quadrant Gaussian primes whose norm is less than 10^n.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GaussianPrime.html">Gaussian Prime</a>

%H <a href="/index/Ga#gaussians">Index entries for Gaussian integers and primes</a>

%F a(2n) = 2*A091098(2n) + 2*A091099(n) + 1.

%t 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, 0, lim1}, {y, 0, lim1}]; cnt, {n, 6}]

%Y Cf. A091098 (number of primes of the form 4k+1 less than 10^n), A091099 (number of primes of the form 4k+3 less than 10^n), A091100, A091102.

%K nonn,more

%O 1,1

%A _T. D. Noe_, Dec 19 2003

%E a(10) calculated from the data at A091098 and A091099 by _Amiram Eldar_, Feb 28 2020

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 4 23:18 EDT 2023. Contains 365888 sequences. (Running on oeis4.)