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%I #33 Jan 15 2021 06:04:54
%S 0,12,26,42,60,80,102,126,152,180,210,242,276,312,350,390,432,476,522,
%T 570,620,672,726,782,840,900,962,1026,1092,1160,1230,1302,1376,1452,
%U 1530,1610,1692,1776,1862,1950,2040,2132,2226,2322,2420,2520
%N a(n) = n*(n+11).
%H Felix P. Muga II, <a href="https://www.researchgate.net/publication/267327689_Extending_the_Golden_Ratio_and_the_Binet-de_Moivre_Formula">Extending the Golden Ratio and the Binet-de Moivre Formula</a>, Preprint on ResearchGate, March 2014.
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F Equals 2 * A056115. - _Zerinvary Lajos_, Feb 12 2007
%F a(n) = 2*a(n-1) - a(n-2) + 2 with a(0)=0, a(1)=12. - _Vincenzo Librandi_, Aug 01 2010
%F G.f.: 2*x*(-6+5*x) / (x-1)^3 . - _R. J. Mathar_, Jul 14 2012
%F Sum_{n>=1} 1/a(n) = 83711/304920 via Sum_{n>=0} 1/((n+x)(n+y)) = (psi(x)-psi(y))/(x-y). - _R. J. Mathar_, Jul 14 2012
%F Sum_{n>=1} (-1)^(n+1)/a(n) = 2*log(2)/11 - 20417/304920. - _Amiram Eldar_, Jan 15 2021
%t s=0;lst={s};Do[s+=n++ +12;AppendTo[lst, s], {n, 0, 7!, 2}];lst (* _Vladimir Joseph Stephan Orlovsky_, Nov 19 2008 *)
%t Table[n(n+11),{n,0,100}] (* _Vladimir Joseph Stephan Orlovsky_, May 19 2011 *)
%t LinearRecurrence[{3,-3,1},{0,12,26},50] (* _Harvey P. Dale_, Jun 11 2016 *)
%o (PARI) a(n)=n*(n+11) \\ _Charles R Greathouse IV_, Jan 21 2015
%Y Cf. A056115, A063930.
%K easy,nonn
%O 0,2
%A _Zerinvary Lajos_, Jul 26 2006
%E Definition simplified and the most obfuscating programs removed by _R. J. Mathar_, Jul 31 2010
%E Offset corrected (from 11 to 0) by _Vincenzo Librandi_, Aug 01 2010
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