%I A005257 M0716
%S A005257 2,3,5,9,17,33,64,126,249,495,984,1962,3913,7815,15608,31194,62346,
%T A005257 124650,249216,498348,996531,1992897,3985464,7970598,15940542,31880430,
%U A005257 63759552,127517796,255032987,510063369,1020121528,2040237846,4080465294,
               8160920190
%N A005257 Number of weighted voting procedures.
%C A005257 Appears to satisfy a(1)=2, a(2)=3, a(3)=5 and, for n>3, a(n)=3a(n-1)-2a(n-2) 
               if n is even and a(n)=a(n-1)+2a(n-2)-a([(n-1)/2]-1) if n is odd - 
               John W. Layman (layman(AT)math.vt.edu), Jan 10 2000.
%D A005257 G. Kreweras, Sur quelques problemes relatifs au vote pondere [Some problems 
               of weighted voting], Math. Sci. Humaines No. 84 (1983), 45-63.
%D A005257 T. V. Narayana, Recent progress and unsolved problems in dominance theory, 
               pp. 68-78 of Combinatorial mathematics (Canberra 1977), Lect. Notes 
               Math. Vol. 686, 1978.
%D A005257 T. V. Narayana, Lattice Path Combinatorics with Statistical Applications. 
               Univ. Toronto Press, 1979, pp. 100-101.
%D A005257 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%t A005257 a={2, 3, 5}; For[i=4, i<35, i++, If[EvenQ[i], a=Append[a, 3 a[[i-1]]-2a[[i-2]]], 
               a=Append[a, a[[i-1]]+2a[[i-2]]-a[[(i-1)/2-1]]]]]; a
%Y A005257 Sequence in context: A080889 A049858 A092483 this_sequence A091697 A109740 
               A000051
%Y A005257 Adjacent sequences: A005254 A005255 A005256 this_sequence A005258 A005259 
               A005260
%K A005257 nonn,easy,nice
%O A005257 1,1
%A A005257 N. J. A. Sloane (njas(AT)research.att.com).
%E A005257 More terms from Vit Planocka (planocka(AT)mistral.cz), Sep 20 2002