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 A091101 Number of first-quadrant Gaussian primes whose norm is less than 10^n. 2
 5, 27, 173, 1245, 9635, 78525, 664811, 5762247, 50850399, 455056167 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..10. Eric Weisstein's World of Mathematics, Gaussian Prime Index entries for Gaussian integers and primes FORMULA a(2n) = 2*A091098(2n) + 2*A091099(n) + 1. MATHEMATICA Table[lim2=10^n; lim1=Floor[Sqrt[lim2]]; cnt=0; Do[If[x^2+y^2True], cnt++ ], {x, 0, lim1}, {y, 0, lim1}]; cnt, {n, 6}] CROSSREFS 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. Sequence in context: A225344 A109963 A201870 * A185622 A225309 A231091 Adjacent sequences: A091098 A091099 A091100 * A091102 A091103 A091104 KEYWORD nonn,more AUTHOR T. D. Noe, Dec 19 2003 EXTENSIONS a(10) calculated from the data at A091098 and A091099 by Amiram Eldar, Feb 28 2020 STATUS approved

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Last modified June 10 09:03 EDT 2023. Contains 363196 sequences. (Running on oeis4.)