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A269163
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Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton; range of A269160 sorted into ascending order.
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6
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0, 7, 13, 14, 25, 26, 27, 28, 49, 50, 51, 52, 53, 54, 56, 63, 97, 98, 99, 100, 101, 102, 104, 105, 106, 107, 108, 111, 112, 119, 125, 126, 193, 194, 195, 196, 197, 198, 200, 201, 202, 203, 204, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 221, 222, 223, 224, 231, 237, 238, 249, 250, 251, 252, 385, 386, 387, 388
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OFFSET
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0,2
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COMMENTS
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Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton. The configuration of white and black cells is encoded in the binary representation (A007088) of each number.
The indexing starts from zero, because a(0) = 0 is a special case in this sequence. (Zero is the only number which is its own predecessor).
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LINKS
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Eric Weisstein's World of Mathematics, Rule 30
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MATHEMATICA
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terms = 100; Clear[f]; f[max_] := f[max] = Sort[Table[BitXor[n, BitOr[2n, 4n]], {n, 0, max}]][[1 ;; terms]]; f[terms]; f[max = 2 terms]; While[ Print[max]; f[max] != f[max/2], max = 2 max]; A269163 = f[max] (* Jean-François Alcover, Feb 23 2016 *)
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PROG
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(define A269163 (MATCHING-POS 0 0 (lambda (n) (or (zero? n) (not (zero? (A269162 n)))))))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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