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 A282083 #6 Sep 18 2024 09:43:08
%S A282083 1,4,16,60,170,396,848,1716,3235,5720,9696,15912,25236,38760,58080,
%T A282083 85272,122661,173052,240240,328900,444158,592020,780208,1017900,
%U A282083 1315015,1682928,2135744,2689808,3362600,4173840,5147328,6310128,7690953,9321780,11240400
%N A282083 Number of n-element subsets of [n+7] having an even sum.
%H A282083 Alois P. Heinz, <a href="/A282083/b282083.txt">Table of n, a(n) for n = 0..1000</a>
%H A282083 <a href="/index/Rec#order_16">Index entries for linear recurrences with constant coefficients</a>, signature (8, -32, 88, -188, 328, -480, 600, -646, 600, -480, 328, -188, 88, -32, 8, -1).
%F A282083 G.f.: (x^8-4*x^7+16*x^6-28*x^5+38*x^4-28*x^3+16*x^2-4*x+1) / ((x^2+1)^4*(x-1)^8).
%F A282083 a(n) = A282011(n+7,n).
%e A282083 a(0) = 1: {}.
%e A282083 a(1) = 4: {2}, {4}, {6}, {8}.
%e A282083 a(2) = 16: {1,3}, {1,5}, {1,7}, {1,9}, {2,4}, {2,6}, {2,8}, {3,5}, {3,7}, {3,9}, {4,6}, {4,8}, {5,7}, {5,9}, {6,8}, {7,9}.
%Y A282083 Cf. A282011.
%K A282083 nonn,easy
%O A282083 0,2
%A A282083 _Alois P. Heinz_, Feb 05 2017