%I A094833
%S A094833 1,4,15,55,199,714,2548,9061,32148,113887,403051,1425471,5039254,
%T A094833 17809336,62928201,222324436,785402143,2774421135,9800231959,
%U A094833 34617003682,122274355596,431893332397,1525507797700,5388281150223
%N A094833 Number of (s(0), s(1), ..., s(2n)) such that 0 < s(i) < 9 and |s(i) - 
               s(i-1)| = 1 for i = 1,2,....,2n, s(0) = 3, s(2n) = 5.
%C A094833 In general a(n)= (2/m)*Sum(r,1,m-1,Sin(r*j*Pi/m)Sin(r*k*Pi/m)(2Cos(r*Pi/
               m))^(2n)) counts (s(0), s(1), ..., s(2n)) such that 0 < s(i) < m 
               and |s(i)-s(i-1)| = 1 for i = 1,2,....,2n, s(0) = j, s(2n) = k.
%F A094833 a(n+1)=3*a(n)+A094832(n-1) . - Philippe DELEHAM, Mar 20 2007
%F A094833 a(n)=(2/9)*Sum(r, 1, 8, Sin(r*Pi/3)Sin(5*r*Pi/9)(2Cos(r*Pi/9))^(2n)) 
               a(n)=6a(n-1)-9a(n-2)+a(n-3) G.f.: (-x+2x^2)/(-1+6x-9x^2+x^3)
%Y A094833 Sequence in context: A002311 A102349 A126932 this_sequence A039717 A026013 
               A050183
%Y A094833 Adjacent sequences: A094830 A094831 A094832 this_sequence A094834 A094835 
               A094836
%K A094833 nonn
%O A094833 1,2
%A A094833 Herbert Kociemba (kociemba(AT)t-online.de), Jun 13 2004