cp's OEIS Frontend

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.

A082679 Number of LEGO towers, one piece per floor, where every floor is perpendicular to the one below it (so we have a kind of 3-dimensional zigzag pattern).

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%I A082679 #11 Oct 11 2022 22:57:45
%S A082679 0,1,2,6,20,69,241,845,2966,10414,36568,128409,450913,1583401,5560186,
%T A082679 19524854,68562444,240760253,845440977,2968805845,10425101678,
%U A082679 36608235998,128551546480,451414815601,1585164405441
%N A082679 Number of LEGO towers, one piece per floor, where every floor is perpendicular to the one below it (so we have a kind of 3-dimensional zigzag pattern).
%H A082679 D. Zeilberger, <a href="http://arXiv.org/abs/math.CO/9801016">[math/9801016] Automated counting of LEGO towers</a>
%H A082679 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (5,-6,3,-1).
%F A082679 G.f.: x*(1 - 3*x + 2*x^2 - x^3)/(1 - 5*x + 6*x^2 - 3*x^3 + x^4).
%t A082679 CoefficientList[Series[x*(1 - 3*x + 2*x^2 - x^3)/(1 - 5*x + 6*x^2 - 3*x^3 + x^4), {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Feb 12 2017 *)
%t A082679 LinearRecurrence[{5,-6,3,-1},{0,1,2,6,20},30] (* _Harvey P. Dale_, Nov 10 2021 *)
%K A082679 nonn,easy
%O A082679 0,3
%A A082679 _Ralf Stephan_, May 19 2003