%I A071402
%S A071402 0,2,17,59,140,273,471,748,1117,1590,2182,2904,3770,4793,5987,7363,
%T A071402 8936,10719,12724,14964,17454,20205,23231,26545,30160,34089,38345,
%U A071402 42942,47893,53209,58906,64995,71490,78404,85749,93540,101789,110509
%N A071402 Rounded volume of a regular icosahedron with edge length n.
%C A071402 The printed reference given shows in a table on p. 10 that Volume is 
               "2.18170a^3" (a is edge). Both PARI (see Example here) and a handheld 
               calculator show that 2.18169 is correct for a 5-decimal-place approximation.
%D A071402 S. Selby, editor, CRC Basic Mathematical Tables, CRC Press, 1970, pp. 
               10-11.
%H A071402 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Icosahedron.html">Link to a section of The World of Mathematics</
               a>
%F A071402 a(n) = round(n^3 * (3+sqrt(5)) * 5/12)
%e A071402 a(6)=471 because round(6^3*(3+sqrt(5))*5/12)=round(216*2.181694990...)=round(471.24...)=471.
%o A071402 (PARI) for(n=0,100,print1(round(n^3*(3+sqrt(5))*5/12),","))
%Y A071402 Cf. A000578 (cube), A071399 (tetrahedron), A071400 (octahedron), A071401 
               (dodecahedron), A071398 (total surface area of icosahedron).
%Y A071402 Sequence in context: A125609 A100518 A125200 this_sequence A002430 A160469 
               A037420
%Y A071402 Adjacent sequences: A071399 A071400 A071401 this_sequence A071403 A071404 
               A071405
%K A071402 easy,nonn
%O A071402 0,2
%A A071402 Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 29 2002