cp's OEIS Frontend

A062186 a(n) = a(n-1) - a(floor(n/2)), with a(1)=1.

%I A062186 #12 Jun 09 2022 02:24:47
%S A062186 1,0,-1,-1,-1,0,1,2,3,4,5,5,5,4,3,1,-1,-4,-7,-11,-15,-20,-25,-30,-35,
%T A062186 -40,-45,-49,-53,-56,-59,-60,-61,-60,-59,-55,-51,-44,-37,-26,-15,0,15,
%U A062186 35,55,80,105,135,165,200,235,275,315,360,405,454,503,556,609,665,721,780,839,899,959,1020,1081,1141,1201,1260
%N A062186 a(n) = a(n-1) - a(floor(n/2)), with a(1)=1.
%C A062186 Period of oscillations above and below the axis more than doubles at each cycle.
%F A062186 G.f.: A(x) satisfies: A(x) = (x - (1 + x)*A(x^2))/(1 - x). - _Ilya Gutkovskiy_, May 04 2019
%e A062186 a(14) = a(13) - a(7) = 5 - 1 = 4.
%e A062186 a(15) = a(14) - a(7) = 4 - 1 = 3.
%o A062186 (Python)
%o A062186 from itertools import islice
%o A062186 from collections import deque
%o A062186 def A062186_gen(): # generator of terms
%o A062186     aqueue, f, b, a = deque([0]), True, 1, 0
%o A062186     yield from (1,0)
%o A062186     while True:
%o A062186         a -= b
%o A062186         yield a
%o A062186         aqueue.append(a)
%o A062186         if f: b = aqueue.popleft()
%o A062186         f = not f
%o A062186 A062186_list = list(islice(A062186_gen(),40)) # _Chai Wah Wu_, Jun 08 2022
%Y A062186 Cf. A033485, A062187, A062188.
%K A062186 sign
%O A062186 1,8
%A A062186 _Henry Bottomley_, Jun 13 2001