%I A052951
%S A052951 1,5,14,36,88,208,480,1088,2432,5376,11776,25600,55296,118784,253952,
%T A052951 540672,1146880,2424832,5111808,10747904,22544384,47185920,98566144,
%U A052951 205520896,427819008,889192448,1845493760,3825205248,7918845952
%N A052951 A simple regular expression.
%C A052951 Equals binomial transform of A042948 starting with "1": (1, 4, 5, 8, 
               9, 12, 13,...) = terms >0, == 0 or 1 mod 4. [From Gary W. Adamson 
               (qntmpkt(AT)yahoo.com), Feb 07 2009]
%H A052951 INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=1021">
               Encyclopedia of Combinatorial Structures 1021</a>
%F A052951 G.f.: -(-x+2*x^2-1)/(-1+2*x)^2
%F A052951 Recurrence: {a(0)=1, 4*a(n)-4*a(n+1)+a(n+2), a(1)=5, a(2)=14}
%F A052951 2^n*n+2^n+2^(n-1).
%F A052951 a(n) = A118413(n+1,n-1) for n>2. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Apr 27 2006
%p A052951 spec := [S,{S=Prod(Union(Sequence(Union(Z,Z)),Z),Sequence(Union(Z,Z)))},
               unlabeled ]: seq(combstruct[count ](spec,size=n), n=0..20);
%Y A052951 A042948 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Feb 07 2009]
%Y A052951 Sequence in context: A027983 A142585 A097507 this_sequence A048745 A127980 
               A054486
%Y A052951 Adjacent sequences: A052948 A052949 A052950 this_sequence A052952 A052953 
               A052954
%K A052951 easy,nonn
%O A052951 0,2
%A A052951 encyclopedia(AT)pommard.inria.fr, Jan 25 2000
%E A052951 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 08 2000