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%I #13 Sep 08 2022 08:45:16
%S 0,3,15,43,94,175,293,455,668,939,1275,1683,2170,2743,3409,4175,5048,
%T 6035,7143,8379,9750,11263,12925,14743,16724,18875,21203,23715,26418,
%U 29319,32425,35743,39280,43043,47039,51275,55758,60495,65493,70759
%N a(n) = (7*n^3 + 6*n^2 + 5*n) / 6.
%C a(n) = A001845(n) - A000292(n+1) = A101164(n+3,3) for n>0.
%F From _Chai Wah Wu_, May 29 2016: (Start)
%F a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
%F G.f.: x*(x^2 + 3*x + 3)/(x - 1)^4.
%F (End)
%o (Magma)[(7*n^3 + 6*n^2 + 5*n) / 6: n in [0..40]]; // _Vincenzo Librandi_, Dec 26 2010
%Y Cf. A005449, A101166.
%K nonn
%O 0,2
%A _Reinhard Zumkeller_, Dec 03 2004
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