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a(n) = (n^6 + 2n^5 + 2n^4 + n^3 + 2n)/2.
1

%I #25 Mar 08 2018 12:07:24

%S 4,86,705,3364,11630,32514,78211,168200,331704,610510,1062149,1763436,

%T 2814370,4342394,6507015,9504784,13574636,19003590,26132809,35364020,

%U 47166294,62083186,80740235,103852824,132234400,166805054,208600461

%N a(n) = (n^6 + 2n^5 + 2n^4 + n^3 + 2n)/2.

%C Before this sequence, a(5) = 11630 was an uninteresting number, see Links section. - _Omar E. Pol_, Apr 25 2016

%H Charles R Greathouse IV, <a href="/A163279/b163279.txt">Table of n, a(n) for n = 1..1000</a>

%H Charles R Greathouse IV, <a href="http://math.crg4.com/uninteresting.html">Uninteresting numbers</a>

%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7,-21,35,-35,21,-7,1).

%F G.f.: x*(4 + 58*x + 187*x^2 + 95*x^3 + 17*x^4 - x^5)/(1 - x)^7. - _Ilya Gutkovskiy_, Apr 25 2016

%t Array[Function[n, (n^6 + 2 n^5 + 2 n^4 + n^3 + 2 n)/2], {27}] (* or *)

%t Rest@ CoefficientList[Series[x (4 + 58 x + 187 x^2 + 95 x^3 + 17 x^4 - x^5)/(1 - x)^7, {x, 0, 27}], x] (* _Michael De Vlieger_, Apr 25 2016 *)

%t LinearRecurrence[{7,-21,35,-35,21,-7,1},{4,86,705,3364,11630,32514,78211},30] (* _Harvey P. Dale_, Mar 08 2018 *)

%o (MATLAB) for n=1:354 a(n) = n^2*((n*(n+1))^2 + n*(n+1) + 2/n)/2; end

%o % _Kyle Stern_, Jan 05 2010

%o (PARI) a(n)=(n^6+n^3)/2+n^5+n^4+n \\ _Charles R Greathouse IV_, Jul 29 2011

%Y Cf. A000290, A002378, A035287.

%K easy,nonn

%O 1,1

%A _Omar E. Pol_, Nov 07 2009

%E More terms from _Kyle Stern_, Jan 05 2010