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

3, 15, 59, 255, 947, 4095, 15131, 65407, 242627, 1048271, 3874811, 16743551, 62119411, 268369791, 991927259, 4286447359, 15902689155, 68701773199, 253935222715, 1097330432511, 4071076396851, 17587676696575, 65007550988187, 280916526002175, 1042196361379523, 4502448248917967, 16641933085980923, 71914639532751871

Offset: 0

Author

Antti Karttunen, Oct 04 2019

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..1023
• Antti Karttunen, Terms up to a(255) drawn as binary strings, with 1 bit = 3x3 pixels resolution
• Antti Karttunen, Terms up to a(1023) drawn as binary strings, with 1 bit = 1 pixel resolution
• Index entries for sequences related to cellular automata

Crossrefs

Cf. A003986, A051023, A110240, A269160, A163617, A328105 (binary weight of terms).

Cf. also A327971, A327972, A327973, A327976, A328103 for other such combinations.

Programs

PARI

A269160(n) = bitxor(n, bitor(2*n, 4*n));
A110240(n) = if(!n,1,A269160(A110240(n-1)));
A163617(n) = bitor(n,n<<1);
A328104(n) = A163617(A110240(n));
\\ Use this one for writing b-files:
A328104write(up_to) = { my(s=1, n=0); for(n=0,up_to, write("b328104.txt", n, " ", bitor(s, s<<1)); s = A269160(s)); };

Python

def A269160(n): return(n^((n<<1)|(n<<2)))
def genA328104():
    '''Yield successive terms of A328104.'''
    s = 1
    while True:
       yield (s|(s<<1))
       s = A269160(s)

Formula

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

a(n) = (1/2) * (A110240(n) XOR A110240(1+n)).