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%I #19 Sep 07 2022 04:11:05
%S 200,400,600,800,1000,1200,1400,1600,1800,2000,2200,2400,2600,2800,
%T 3000,3200,3400,3600,3800,4000,4200,4400,4600,4800,5000,5200,5400,
%U 5600,5800,6000,6200,6400,6600,6800,7000,7200,7400,7600,7800,8000,8200,8400,8600
%N Sum of the interior angles of an n-sided polygon, in gradians.
%H G. C. Greubel, <a href="/A117412/b117412.txt">Table of n, a(n) for n = 3..5000</a>
%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Gradian.html">Gradian</a>.
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F a(n) = 200*(n-2) for n >= 3.
%F From _G. C. Greubel_, Sep 07 2022: (Start)
%F a(n) = 40*A008587(n-2).
%F G.f.: 200*x^3/(1-x)^2.
%F E.g.f.: 200*(2 + x - (2 - x)*exp(x)). (End)
%t 200*(Range[3,50] -2) (* _G. C. Greubel_, Sep 07 2022 *)
%o (Magma) [200*(n-2): n in [3..50]]; // _G. C. Greubel_, Sep 07 2022
%o (SageMath) [200*(n-2) for n in (3..50)] # _G. C. Greubel_, Sep 07 2022
%Y Cf. A008587.
%K easy,nonn
%O 3,1
%A Luc Stevens (lms022(AT)yahoo.com), Apr 25 2006
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