%I A008464
%S A008464 1,5,24,108,464,1936,7936,32192,129792,521472,2091008,8375296,
%T A008464 33525760,134156288,536739840,2147205120,8589344768,34358493184,
%U A008464 137436332032,549750308864,2199011721216,8796068904960
%N A008464 2^(2*n+3) - 2^n*(n+3).
%C A008464 a(n-2)=2^(2n-1) - (n+1)*2^(n-2) is number of compositions of 2n where 
               each part is less than or equal to n: e.g. for n=2, 4 can be written 
               5 ways with no part greater than 2 as 1+1+1+1=1+1+2=1+2+1=2+1+1=2+2. 
               - Henry Bottomley (se16(AT)btinternet.com), Feb 03 2003
%F A008464 G.f.: 8/(1-4x)-3/(1-2x)-2x/(1-2x)^2+1/x. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Nov 21 2007
%p A008464 f := n->2^(2*n+3)-2^n*(n+3);
%Y A008464 Sequence in context: A099653 A078820 A046724 this_sequence A063001 A000953 
               A081104
%Y A008464 Adjacent sequences: A008461 A008462 A008463 this_sequence A008465 A008466 
               A008467
%K A008464 nonn,easy
%O A008464 -1,2
%A A008464 N. J. A. Sloane (njas(AT)research.att.com).