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 A107850 #16 Mar 14 2024 15:19:23
%S A107850 1,1,1,0,1,1,3,6,7,13,17,24,41,57,91,142,207,325,489,736,1137,1713,
%T A107850 2611,3990,6039,9213,14017,21288,32441,49321,75019,114206,173663,
%U A107850 264245,402073,611568,930561,1415713,2153699,3276838,4985127,7584237,11538801
%N A107850 Expansion of g.f. (x^2+x+1)*(2*x^2+2*x+1)*(x-1)^2/((1-x^2-2*x^3)*(x^4+1)).
%C A107850 Floretion Algebra Multiplication Program, FAMP Code: 1lesforzapseq[(.5i' + .5j' + .5'ki' + .5'kj')*(.5'i + .5'j + .5'ik' + .5'jk')], 1vesforzap = A000004
%H A107850 Harvey P. Dale, <a href="/A107850/b107850.txt">Table of n, a(n) for n = 0..1000</a>
%H A107850 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (0,1,2,-1,0,1,2).
%F A107850 a(n) = A052947(n-1)+A118831(n+6). - _R. J. Mathar_, Apr 18 2008
%F A107850 a(0)=1, a(1)=1, a(2)=1, a(3)=0, a(4)=1, a(5)=1, a(6)=3, a(n)=a(n-2)+ 2*a(n-3)- a(n-4)+a(n-6)+2*a(n-7). - _Harvey P. Dale_, Dec 26 2015
%t A107850 CoefficientList[Series[(x^2+x+1)(2x^2+2x+1)(x-1)^2/((1-x^2-2x^3)(x^4+1)),{x,0,50}],x] (* or *) LinearRecurrence[{0,1,2,-1,0,1,2},{1,1,1,0,1,1,3},50] (* _Harvey P. Dale_, Dec 26 2015 *)
%Y A107850 Cf. A107849, A107851, A107852.
%K A107850 easy,nonn
%O A107850 0,7
%A A107850 _Creighton Dement_, May 25 2005