This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A094311 #21 Jul 01 2025 18:46:02
%S A094311 1,20,210,1309,5720,19536,55825,139490,314019,650440,1258796,2302455,
%T A094311 4015570,6724004,10870035,17041156,26003285,38738700,56489014,
%U A094311 80803505,113593116,157190440,214416005,288651174,383917975,504966176,657367920,847620235,1083255734
%N A094311 a(n) = n*(1+n^2)*((2+n^2)^2-n^2)/16.
%H A094311 Harvey P. Dale, <a href="/A094311/b094311.txt">Table of n, a(n) for n = 1..1000</a>
%H A094311 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (8,-28,56,-70,56,-28,8,-1).
%F A094311 From _Harvey P. Dale_, Oct 17 2011: (Start)
%F A094311 a(1)=1, a(2)=20, a(3)=210, a(4)=1309, a(5)=5720, a(6)=19536, a(7)=55825, a(8)=139490, a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8).
%F A094311 G.f.: (x*(x+1)*(x*(x*(x*(x+11)+67)+66)+12)+1)/(x-1)^8. (End)
%F A094311 a(n) = A064322(n) - A064322(n-1). - _J.S. Seneschal_, Jun 27 2025
%t A094311 Table[n(1+n^2)((2+n^2)^2-n^2)/16,{n,30}] (* or *) LinearRecurrence[ {8,-28,56,-70,56,-28,8,-1},{1,20,210,1309,5720,19536,55825,139490},30] (* _Harvey P. Dale_, Oct 17 2011 *)
%Y A094311 Cf. A000217, A064322.
%K A094311 nonn,easy
%O A094311 1,2
%A A094311 _Amarnath Murthy_, Apr 29 2004
%E A094311 Edited by _N. J. A. Sloane_ following a suggestion from _Zak Seidov_, Mar 28 2008