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A101418
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Floor of the area of a lens constructed using circular arcs of radius n.
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0
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1, 4, 11, 19, 30, 44, 60, 78, 99, 122, 148, 176, 207, 240, 276, 314, 354, 397, 443, 491, 541, 594, 649, 707, 767, 830, 895, 963, 1033, 1105, 1180, 1257, 1337, 1419, 1504, 1591, 1681, 1773, 1868, 1965, 2064, 2166, 2271, 2378, 2487, 2599, 2713, 2830, 2949
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Eric Weisstein's World of Mathematics, "Lens."
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FORMULA
| a(n) = Floor[(4*Pi - 3*Sqrt[3])/6*n^2]
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EXAMPLE
| a(2) = 4 because a lens given by the intersection of two circles of radius two has an area of approximately 4.91347...
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MATHEMATICA
| Table[Floor[(4*Pi - 3*Sqrt[3])/6*r^2], {r, 1, 60}]
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CROSSREFS
| Cf. A093731.
Sequence in context: A063215 A162996 A037262 * A185873 A009874 A008051
Adjacent sequences: A101415 A101416 A101417 * A101419 A101420 A101421
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KEYWORD
| nonn
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AUTHOR
| Joseph Biberstine (jrbibers(AT)indiana.edu), Jan 16 2005
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