login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A327972
Bitwise XOR of trajectories of rule 30 and rule 150, when both are started from a lone 1 cell: a(n) = A110240(n) XOR A038184(n).
7
0, 0, 12, 4, 128, 384, 3404, 740, 37056, 127296, 794316, 286532, 8510656, 25560896, 224057484, 42076324, 2446214016, 8430013568, 51732969356, 18062215300, 553213409792, 1655549411840, 14630859361996, 3227756349540, 159219183713088, 546944274202816, 3411332163636556, 1231354981057220, 36554500089286208, 109782277571646400, 962314238681316620
OFFSET
0,3
FORMULA
a(n) = A038184(n) XOR A110240(n).
Conjecture: for n > 1, floor(log_2(a(n))) = 2*n - (1,2,1,4,1,2,1,5 according as n == 0..7 (mod 8), respectively). - Alan Michael Gómez Calderón, Mar 02 2023
PROG
(PARI)
A048727(n) = bitxor(n, bitxor(2*n, 4*n)); \\ From A048727
A038184(n) = if(!n, 1, A048727(A038184(n-1)));
A269160(n) = bitxor(n, bitor(2*n, 4*n)); \\ From A269160.
A110240(n) = if(!n, 1, A269160(A110240(n-1)));
A327972(n) = bitxor(A038184(n), A110240(n));
\\ Use this one for writing b-files:
A327972write(up_to) = { my(s1=1, s2=1); for(n=0, up_to, write("b327972.txt", n, " ", bitxor(s1, s2)); s1 = A048727(s1); s2 = A269160(s2)); };
(Python)
def A048727(n): return(n^(n<<1)^(n<<2))
def A269160(n): return(n^((n<<1)|(n<<2)))
def genA327972():
'''Yield successive terms of A327972.'''
s1 = 1
s2 = 1
while True:
yield (s1^s2)
s1 = A269160(s1)
s2 = A048727(s2)
CROSSREFS
Cf. also A327971, A327973, A327976, A328103, A328104 for other such combinations.
Sequence in context: A092237 A367323 A081987 * A047709 A002911 A038330
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 03 2019
STATUS
approved