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Search: id:A051132
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| A051132 |
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Number of ordered pairs of integers (x,y) with x^2+y^2 < n^2. |
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+0
7
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| 0, 1, 9, 25, 45, 69, 109, 145, 193, 249, 305, 373, 437, 517, 609, 697, 793, 889, 1005, 1125, 1245, 1369, 1513, 1649, 1789, 1941, 2109, 2285, 2449, 2617, 2809, 2997, 3205, 3405, 3613, 3841, 4049, 4281, 4509, 4765, 5013, 5249, 5521, 5785, 6073, 6349, 6621
(list; graph; listen)
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OFFSET
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0,3
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..1000
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EXAMPLE
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a(3)=25 from the points of shapes 00 (1), 10 (4), 11 (4), 20 (4), 21 (8), 22 (4).
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MATHEMATICA
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Needs["NumberTheory`NumberTheoryFunctions`"]; Table[Sum[SumOfSquaresR[2, k], {k, 0, n^2 - 1}], {n, 0, 46}]
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CROSSREFS
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Changing "<" to "<=" in the definition gives A000328.
Sequence in context: A044451 A114057 A031036 this_sequence A075026 A113659 A113745
Adjacent sequences: A051129 A051130 A051131 this_sequence A051133 A051134 A051135
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KEYWORD
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nonn,nice,easy
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AUTHOR
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Jostein Trondal (jostein.trondal(AT)protech.no)
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EXTENSIONS
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More terms from James A. Sellers (sellersj(AT)math.psu.edu)
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