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A356551 a(n) = A005132(n+2) - A005132(n).

%I A356551 #50 Sep 16 2022 02:13:54
%S A356551 3,5,-1,1,11,13,-1,1,-1,1,-1,1,-1,1,-1,1,35,37,-1,1,-1,-45,1,-1,1,-1,
%T A356551 1,-1,1,-1,1,65,67,-1,1,-1,-75,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,
%U A356551 -1,1,-1,1,-1,1,-1,1,-1,1,-1,1,131,133,-1,1,-1
%N A356551 a(n) = A005132(n+2) - A005132(n).
%H A356551 <a href="/index/Rea#Recaman">Index entries for sequences related to Recamán's sequence</a>
%o A356551 (PARI) vR(nn) = my(s, t, v=vector(nn)); for(n=1, nn, s=bitor(s, 1<<t += if( t<=n || bittest(s, t-n), n, -n)); v[n]=t); concat(0, v); \\ from A005132
%o A356551 lista(nn) = my(v=vR(nn+1)); vector(nn, k, v[k+2] - v[k]); \\ _Michel Marcus_, Aug 14 2022
%o A356551 (Python)
%o A356551 from itertools import count, islice
%o A356551 def A356551_gen(): # generator of terms
%o A356551     b, c, aset = 0, 1, {0}
%o A356551     for n in count(2):
%o A356551         aset.add(c)
%o A356551         a, b, c = b, c, d if (d:=c-n)>=0 and d not in aset else c+n
%o A356551         yield c-a
%o A356551 A356551_list = list(islice(A356551_gen(),70)) # _Chai Wah Wu_, Sep 15 2022
%Y A356551 Cf. A005132, A160356.
%K A356551 sign
%O A356551 0,1
%A A356551 _Paul Curtz_, Aug 12 2022