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 A046672 #24 Dec 29 2023 10:43:08 %S A046672 1,2,7,18,53,146,415,1162,3277,9210,25927,72930,205221,577378,1624559, %T A046672 4570810,12860541,36184394,101808791,286449682,805956949,2267645362, %U A046672 6380262207,17951546602,50508589101,142111293594,399845261287,1125007225154 %N A046672 Expansion of 1/(1-2*x-3*x^2+2*x^3). %H A046672 Iain Fox, <a href="/A046672/b046672.txt">Table of n, a(n) for n = 0..2226</a> %H A046672 Richard M. Low and Ardak Kapbasov, <a href="https://www.emis.de/journals/JIS/VOL20/Low/low2.html">Non-Attacking Bishop and King Positions on Regular and Cylindrical Chessboards</a>, Journal of Integer Sequences, Vol. 20 (2017), Article 17.6.1, Table 6. %H A046672 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2, 3, -2). %F A046672 a(n) = 2*a(n-1) + 3*a(n-2) - 2*a(n-3), n > 2. - _Iain Fox_, Dec 02 2017 %o A046672 (PARI) first(n) = Vec(1/(1-2*x-3*x^2+2*x^3) + O(x^n)) \\ _Iain Fox_, Dec 02 2017 %Y A046672 Partial sums of A054854. %Y A046672 Cf. A101197. %K A046672 nonn,easy %O A046672 0,2 %A A046672 _N. J. A. Sloane_, Nov 17 2002