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A036701 a(n)=number of Gaussian integers z=a+bi satisfying n-1<|z|<=n, a>=0, 0<=b

%I A036701 #12 Dec 18 2018 12:06:18
%S A036701 0,1,1,2,3,4,4,5,6,7,8,8,8,11,11,12,11,13,14,15,16,15,18,17,18,21,20,
%T A036701 21,21,22,24,23,26,25,27,29,25,30,28,33,31,30,33,33,36,36,33,37,37,39,
%U A036701 40,41,41,39,42,42,46,43,46,45,47
%N A036701 a(n)=number of Gaussian integers z=a+bi satisfying n-1<|z|<=n, a>=0, 0<=b<a.
%H A036701 Robert Israel, <a href="/A036701/b036701.txt">Table of n, a(n) for n = 0..2000</a>
%H A036701 <a href="/index/Ga#gaussians">Index entries for Gaussian integers and primes</a>
%p A036701 N:= 100: A:= Array(0..N):
%p A036701 for a from 1 to N do
%p A036701   for b from 0 to a-1 do
%p A036701      r:= ceil(sqrt(a^2+b^2));
%p A036701      if r > N then break fi;
%p A036701      A[r]:= A[r]+1;
%p A036701 od od:
%p A036701 seq(A[i],i=0..N); # _Robert Israel_, Dec 18 2018
%Y A036701 Cf. A036700.
%K A036701 nonn
%O A036701 0,4
%A A036701 _Clark Kimberling_