%I #14 Apr 06 2024 13:31:04

%S -1,2,4,-56,80,-352,64,2176,-4864,31232,-23552,-14336,217088,-2056192,

%T 2375680,-7307264,-4390912,102367232,-169607168,877133824,-397410304,

%U -3042967552,9265217536,-68308434944,62495129600,-78483816448,-342993403904

%N (1,1) entry of powers of the orthogonal design shown below.

%C -1 +1 +1 -1 -1 +1 -1 -1

%C +1 +1 -1 -1 -1 -1 -1 +1

%C +1 +1 +1 +1 +1 +1 -1 +1

%C +1 -1 +1 -1 +1 -1 -1 -1

%C +1 -1 +1 -1 -1 +1 +1 +1

%C +1 +1 -1 -1 +1 +1 +1 -1

%C -1 +1 +1 -1 +1 -1 +1 +1

%C +1 +1 +1 +1 -1 -1 +1 -1

%D S. Severini, A note on two integer sequences arising from the 3-dimensional hypercube, Technical Report, Department of Computer Science, University of Bristol, Bristol, UK (October 2003).

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,4,0,-64).

%F a(0)=1, a(1)=-1, a(2)=2, a(3)=4, a(n) = 4*a(n-2) - 64*a(n-4). - _T. D. Noe_, Dec 11 2006

%F G.f.: -x*(4*x+1)*(16*x^2-6*x+1)/(64*x^4-4*x^2+1). - _Colin Barker_, Aug 10 2012

%K easy,sign

%O 1,2

%A _Simone Severini_, Oct 25 2003

%E Corrected by _T. D. Noe_, Dec 11 2006