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 A178134 #10 May 15 2016 23:36:09 %S A178134 0,1,1,2,-3,-2,-32,-81,-311,-810,-2515,-6864,-19944,-55043,-156023, %T A178134 -433522,-1217427,-3391226,-9488456,-26462205,-73933535,-206293134, %U A178134 -576040339,-1607642688,-4488069168,-12526662167,-34967630447 %N A178134 Sum_{m=0..(n-1)/2} A176263(n-m-1, m). %C A178134 The limiting ratio is (alternating) A222134, 5 times a root of the polynomial 5x^2+x-1 in the denominator of the g.f. %H A178134 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (1,7,-2,-6,-4,-25,5,25). %F A178134 G.f. -x*(1-6*x^2-10*x^3-5*x^4+5*x^5) / ( (x-1)*(1+x)*(5*x^2+x-1)*(5*x^4+x^2-1) ). - _R. J. Mathar_, Nov 05 2012 %p A178134 A178134 := proc(n) %p A178134 add( A176263(n-m-1,m), m=0..(n-1)/2) ; %p A178134 end proc: # _R. J. Mathar_, May 15 2016 %t A178134 Clear[a, f, a0, t] %t A178134 f[0, a_] := 0; f[1, a_] := 1; %t A178134 f[n_, a_] := f[n, a] = f[n - 1, a] + a*f[n - 2, a]; %t A178134 t[n_, m_, a_] := f[m + 1, a] + f[n + 1 - m, a] - f[n + 1, a]; %t A178134 a = 5; %t A178134 a0[n_] := Sum[t[n - m - 1, m, a], {m, 0, Floor[(n - 1)/2]}]; %t A178134 Table[a0[n], {n, 0, 30}] %o A178134 (PARI) a(n)=([0,1,0,0,0,0,0,0; 0,0,1,0,0,0,0,0; 0,0,0,1,0,0,0,0; 0,0,0,0,1,0,0,0; 0,0,0,0,0,1,0,0; 0,0,0,0,0,0,1,0; 0,0,0,0,0,0,0,1; 25,5,-25,-4,-6,-2,7,1]^n*[0;1;1;2;-3;-2;-32;-81])[1,1] \\ _Charles R Greathouse IV_, May 15 2016 %Y A178134 Cf. A000800, A004148. %K A178134 sign,easy %O A178134 0,4 %A A178134 _Roger L. Bagula_, May 20 2010 %E A178134 New name from _R. J. Mathar_, May 15 2016