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a(n) = (4*n+2)^4.
2

%I #18 Sep 08 2022 08:44:41

%S 16,1296,10000,38416,104976,234256,456976,810000,1336336,2085136,

%T 3111696,4477456,6250000,8503056,11316496,14776336,18974736,24010000,

%U 29986576,37015056,45212176,54700816,65610000,78074896,92236816

%N a(n) = (4*n+2)^4.

%H Vincenzo Librandi, <a href="/A016828/b016828.txt">Table of n, a(n) for n = 0..10000</a>

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1)

%F a(n) = 16*A016756(n). O.g.f.: -16*(1+76*x+230*x^2+76*x^3+x^4)/(-1+x)^5. - _R. J. Mathar_, Mar 31 2008

%F From _Ilya Gutkovskiy_, Jun 21 2016: (Start)

%F a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5).

%F Sum_{n>=0} 1/a(n) = Pi^4/1536. (End)

%t Table[(4n+2)^4,{n,0,100}] (* _Mohammad K. Azarian_, Jun 21 2016 *)

%o (Magma) [(4*n+2)^4: n in [0..40]]; // _Vincenzo Librandi_, Sep 07 2011

%K nonn,easy

%O 0,1

%A _N. J. A. Sloane_.

%E More terms from _R. J. Mathar_, Mar 31 2008