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 A359329 #30 Oct 02 2024 07:40:09
%S A359329 0,0,5,6,14,16,27,30,44,48,65,70,90,96,119,126,152,160,189,198,230,
%T A359329 240,275,286,324,336,377,390,434,448,495,510,560,576,629,646,702,720,
%U A359329 779,798,860,880,945,966,1034,1056,1127,1150,1224,1248,1325,1350,1430,1456,1539,1566,1652,1680
%N A359329 Number of diagonals in a regular polygon with n sides not passing through the center.
%H A359329 Paolo Xausa, <a href="/A359329/b359329.txt">Table of n, a(n) for n = 3..10000</a>
%H A359329 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,2,-2,-1,1).
%F A359329 If n is odd, a(n) = (n^2 - 3*n)/2; if n is even, a(n) = (n^2 - 4*n)/2.
%F A359329 a(n) = A000096(n-3) - A142150(n-3).
%F A359329 G.f.: x^5*(5 + x - 2*x^2)/((1 - x)^3*(1 + x)^2). - _Stefano Spezia_, Jan 04 2023
%t A359329 Table[(n*(n - 4 + BitGet[n, 0]))/2, {n, 3, 100}] (* _Paolo Xausa_, Oct 02 2024 *)
%o A359329 (Python)
%o A359329 def A359329(n): return (n*(n-4)+n*(n&1))>>1 # _Chai Wah Wu_, Jan 23 2023
%Y A359329 A014106 and A054000 interleaved.
%Y A359329 Cf. A000096, A142150.
%K A359329 nonn,easy
%O A359329 3,3
%A A359329 _Luk De Clercq_, Dec 26 2022