%I #9 Apr 29 2017 14:53:31
%S 0,1,2,3,5,9,16,29,54,103,199,388,762,1505,2983,5928,11802,23528,
%T 46948,93743,187270,374234,748036,1495461,2990058,5978894,11956059,
%U 23909673,47815889,95626889,191246864,382483950,764954071,1529888585,3059749513
%N a(n) = a(n-1)*2 - floor(sqrt(a(n-2))).
%H Harvey P. Dale, <a href="/A182558/b182558.txt">Table of n, a(n) for n = 0..1000</a>
%F a(0)=0, a(1)=1, a(n) = a(n-1)*2 - floor(sqrt(a(n-2))).
%t nxt[{a_,b_}]:={b,2b-Floor[Sqrt[a]]}; NestList[nxt,{0,1},40][[All,1]] (* _Harvey P. Dale_, Apr 29 2017 *)
%o (Python)
%o import math
%o prpr = 0
%o prev = 1
%o for n in range(55):
%o . current = prev*2 - int(math.sqrt(prpr))
%o . print prpr,
%o . prpr = prev
%o . prev = current
%Y Cf. A076677, A076678, A182557.
%K nonn
%O 0,3
%A _Alex Ratushnyak_, May 05 2012