%I #18 Jul 04 2019 20:07:22
%S 0,1,1,2,2,3,4,5,7,9,12,15,20,25,33,42,54,69,89,114,146,187,240,307,
%T 394,504,646,827,1060,1357,1739,2227,2853,3654,4680,5994,7677,9833,
%U 12594,16130,20659,26460,33889,43405,55592,71201,91193,116798,149592
%N a(n) = ceiling(a(n-1)/2) + a(n-2) with a(0)=0 and a(1)=1.
%H Reinhard Zumkeller, <a href="/A064651/b064651.txt">Table of n, a(n) for n = 0..9300</a>
%F a(n) = A064650(n) - 1.
%F Lim_{n->infinity} a(n)/a(n-1) = (1+sqrt(17))/4 = 1.2807764... = A188934.
%t RecurrenceTable[{a[0]==0, a[1]==1, a[n]==Ceiling[a[n-1]/2]+a[n-2]}, a, {n,50}] (* _Harvey P. Dale_, Aug 22 2012 *)
%t t = {0, 1}; Do[AppendTo[t, Ceiling[t[[-1]]/2] + t[[-2]]], {48}]; t (* _T. D. Noe_, Aug 22 2012 *)
%o (Haskell)
%o a064651 n = a064651_list !! n
%o a064651_list = 0 : 1 : zipWith (+)
%o a064651_list (map (flip div 2 . (+ 1)) $ tail a064651_list)
%o -- _Reinhard Zumkeller_, Apr 30 2015
%Y Cf. A064324, A064325.
%Y Cf. A064650, A000045, A188934.
%K nonn
%O 0,4
%A _Henry Bottomley_, Oct 04 2001