cp's OEIS Frontend

A328104 a(n) = A163617(A110240(n)) = A110240(n) OR 2*A110240(n).

%I A328104 #17 Oct 05 2019 18:21:16
%S A328104 3,15,59,255,947,4095,15131,65407,242627,1048271,3874811,16743551,
%T A328104 62119411,268369791,991927259,4286447359,15902689155,68701773199,
%U A328104 253935222715,1097330432511,4071076396851,17587676696575,65007550988187,280916526002175,1042196361379523,4502448248917967,16641933085980923,71914639532751871
%N A328104 a(n) = A163617(A110240(n)) = A110240(n) OR 2*A110240(n).
%H A328104 Antti Karttunen, <a href="/A328104/b328104.txt">Table of n, a(n) for n = 0..1023</a>
%H A328104 Antti Karttunen, <a href="/A328104/a328104.png">Terms up to a(255) drawn as binary strings, with 1 bit = 3x3 pixels resolution</a>
%H A328104 Antti Karttunen, <a href="/A328104/a328104_1.png">Terms up to a(1023) drawn as binary strings, with 1 bit = 1 pixel resolution</a>
%H A328104 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%F A328104 a(n) = A163617(A110240(n)) = A110240(n) OR 2*A110240(n).
%F A328104 a(n) = (1/2) * (A110240(n) XOR A110240(1+n)).
%o A328104 (PARI)
%o A328104 A269160(n) = bitxor(n, bitor(2*n, 4*n));
%o A328104 A110240(n) = if(!n,1,A269160(A110240(n-1)));
%o A328104 A163617(n) = bitor(n,n<<1);
%o A328104 A328104(n) = A163617(A110240(n));
%o A328104 \\ Use this one for writing b-files:
%o A328104 A328104write(up_to) = { my(s=1, n=0); for(n=0,up_to, write("b328104.txt", n, " ", bitor(s, s<<1)); s = A269160(s)); };
%o A328104 (Python)
%o A328104 def A269160(n): return(n^((n<<1)|(n<<2)))
%o A328104 def genA328104():
%o A328104     '''Yield successive terms of A328104.'''
%o A328104     s = 1
%o A328104     while True:
%o A328104        yield (s|(s<<1))
%o A328104        s = A269160(s)
%Y A328104 Cf. A003986, A051023, A110240, A269160, A163617, A328105 (binary weight of terms).
%Y A328104 Cf. also A327971, A327972, A327973, A327976, A328103 for other such combinations.
%K A328104 nonn
%O A328104 0,1
%A A328104 _Antti Karttunen_, Oct 04 2019