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1, 8, 12, 16, 32, 28, 40, 40, 48, 68, 56, 72, 68, 88, 88, 84, 112, 112, 112, 116, 112, 144, 140, 144, 144, 168, 164, 160, 184, 172, 200, 192, 188, 208, 224, 224, 228, 224, 248, 236, 264, 248, 264, 276, 264, 288, 276, 304, 304, 312
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OFFSET
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0,2
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COMMENTS
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Number of integer cartesian grid points covered by a ring around the origin with width 1 and outer radius n+0.5. - Ralf Stephan, Nov 28 2013
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LINKS
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Table of n, a(n) for n=0..49.
Index entries for Gaussian integers and primes
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PROG
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(PARI) a(n)=sum(i=-n, n, sum(j=-n, n, d=sqrt(i*i+j*j); if(d>=n-1/2&&d<=n+1/2, 1))) \\ Ralf Stephan, Nov 28 2013
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CROSSREFS
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Cf. A047077, A232705.
Sequence in context: A190037 A110558 A163283 * A129150 A175975 A030752
Adjacent sequences: A036702 A036703 A036704 * A036706 A036707 A036708
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KEYWORD
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nonn
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AUTHOR
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Clark Kimberling
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EXTENSIONS
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Edited by Ralf Stephan, Nov 28 2013
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STATUS
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approved
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