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a(n) = n * (n+1)^2 * (3*n^2 + 4*n + 2) / 12.
1

%I #13 Mar 15 2019 23:28:03

%S 0,3,33,164,550,1455,3283,6608,12204,21075,34485,53988,81458,119119,

%T 169575,235840,321368,430083,566409,735300,942270,1193423,1495483,

%U 1855824,2282500,2784275,3370653,4051908,4839114,5744175,6779855

%N a(n) = n * (n+1)^2 * (3*n^2 + 4*n + 2) / 12.

%C Sums of rows of the triangle in A132121.

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1).

%F G.f.: x*(3 + 15*x + 11*x^2 + x^3)/(1-x)^6. - _Emeric Deutsch_, Aug 19 2007

%p seq((1/12)*n*(n+1)^2*(3*n^2+4*n+2),n=0..32); # _Emeric Deutsch_, Aug 19 2007

%K nonn,easy

%O 0,2

%A _Reinhard Zumkeller_, Aug 12 2007