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A071397
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Rounded total surface area of a regular dodecahedron with edge length n.
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5
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0, 21, 83, 186, 330, 516, 743, 1012, 1321, 1672, 2065, 2498, 2973, 3489, 4047, 4645, 5285, 5967, 6689, 7453, 8258, 9105, 9993, 10922, 11892, 12904, 13957, 15051, 16186, 17363, 18581, 19841, 21141, 22483, 23866, 25291, 26757, 28264, 29812
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OFFSET
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0,2
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REFERENCES
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S. Selby, editor, CRC Basic Mathematical Tables, CRC Press, 1970, pp. 10-11.
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LINKS
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FORMULA
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a(n) = round(3 * n^2 * sqrt(25 + 10*sqrt(5))).
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EXAMPLE
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a(4)=330 because round(3*4^2*sqrt(25 + 10*sqrt(5))) = round(48*6.88190...) = round(330.331...) = 330.
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MATHEMATICA
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With[{c=3*Sqrt[25+10*Sqrt[5]]}, Round[c*Range[0, 40]^2]] (* Harvey P. Dale, Jul 06 2018 *)
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PROG
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(PARI) for(n=0, 100, print1(round(3*n^2*sqrt(25+10*sqrt(5))), ", "))
(Magma) [Round(3 * n^2 * Sqrt(25+10*Sqrt(5))): n in [0..50]]; // Vincenzo Librandi, May 21 2011
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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