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A172526 a(n)=floor(3*n^2*(2+sqrt(3))). 2

%I #12 Sep 08 2022 08:45:50

%S 11,44,100,179,279,403,548,716,906,1119,1354,1612,1892,2194,2519,2866,

%T 3235,3627,4041,4478,4937,5418,5922,6448,6997,7568,8161,8777,9415,

%U 10076,10759,11464,12192,12942,13715,14510,15327,16167,17029,17913,18820

%N a(n)=floor(3*n^2*(2+sqrt(3))).

%C Approximate area of the dodecahedron of side n=(1,2,3,4,...).

%H Vincenzo Librandi, <a href="/A172526/b172526.txt">Table of n, a(n) for n = 1..1000</a>

%t With[{c=3(2+Sqrt[3])},Floor[c Range[50]^2]] (* _Harvey P. Dale_, Apr 01 2011 *)

%t f[n_]:=Floor[3 n^2 (2 + Sqrt[3])]; Array[f, 50, 1] (* _Vincenzo Librandi_, Aug 20 2014 *)

%o (Magma) [Floor(3*n^2*(2+Sqrt(3))): n in [1..50]]; // _Vincenzo Librandi_, Aug 20 2014

%Y Cf. A071401.

%K nonn

%O 1,1

%A _Vincenzo Librandi_, Feb 06 2010

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Last modified April 25 10:22 EDT 2024. Contains 371967 sequences. (Running on oeis4.)