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%I #27 Jul 15 2018 13:53:30
%S 0,10,41,93,166,260,375,511,668,846,1045,1265,1506,1768,2051,2355,
%T 2680,3026,3393,3781,4190,4620,5071,5543,6036,6550,7085,7641,8218,
%U 8816,9435,10075,10736,11418,12121
%N a(n) = n*(21*n-1)/2.
%H G. C. Greubel, <a href="/A022278/b022278.txt">Table of n, a(n) for n = 0..5000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F a(n) = 21*n + a(n-1) - 11 for n > 0, a(0)=0. - _Vincenzo Librandi_, Aug 04 2010
%F G.f.: x*(10 + 11*x)/(1 - x)^3. - _R. J. Mathar_, Aug 04 2016
%F a(n) = A000217(11*n-1) - A000217(10*n-1). - _Bruno Berselli_, Oct 17 2016
%F E.g.f.: (x/2)*(21*x + 20)*exp(x). - _G. C. Greubel_, Aug 23 2017
%t Table[n (21 n - 1)/2, {n, 0, 100}] (* _Vladimir Joseph Stephan Orlovsky_, Mar 07 2011 *)
%o (PARI) a(n)=n*(21*n-1)/2 \\ _Charles R Greathouse IV_, Jun 16 2017
%Y Cf. A000217, A022278.
%Y Cf. similar sequences listed in A022288.
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_
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