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 A047663 #21 Mar 03 2024 10:59:13
%S A047663 6,42,188,644,1826,4494,9912,20040,37758,67122,113652,184652,289562,
%T A047663 440342,651888,942480,1334262,1853754,2532396,3407124,4520978,5923742,
%U A047663 7672616,9832920,12478830,15694146,19573092,24221148,29755914,36308006
%N A047663 Row 6 of square array defined in A047662.
%H A047663 Muniru A Asiru, <a href="/A047663/b047663.txt">Table of n, a(n) for n = 1..10000</a>
%H A047663 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7, -21, 35, -35, 21, -7, 1).
%F A047663 a(n) = (n/45) * (2n^5 + 6n^4 + 35n^3 + 60n^2 + 98n + 69).
%F A047663 From _Chai Wah Wu_, Nov 01 2018: (Start)
%F A047663 a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n > 7.
%F A047663 G.f.: x*(-6*x^4 - 20*x^2 - 6)/(x - 1)^7. (End)
%p A047663 seq(coeff(series(x*(-6*x^4-20*x^2-6)/(x-1)^7,x,n+1), x, n), n = 1 .. 35); # _Muniru A Asiru_, Nov 21 2018
%t A047663 LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {6, 42, 188, 644, 1826, 4494, 9912 }, 50] (* or *)
%t A047663 CoefficientList[Series[-((2 (3 + 10 x^2 + 3 x^4))/(-1 + x)^7), {x, 0, 50}], x] (* _Stefano Spezia_, Nov 01 2018 *)
%o A047663 (GAP) List([1..35],n->n/45*(2*n^5+6*n^4+35*n^3+60*n^2+98*n+69)); # _Muniru A Asiru_, Nov 21 2018
%K A047663 nonn
%O A047663 1,1
%A A047663 _N. J. A. Sloane_