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 A367033 Von Neumann ordinals in bracket notation encoded by binary bits: '{' -> 0, '}'-> 1. 2
 1, 3, 39, 9807, 642665631, 2760227864398567743, 50917216999682251351660181504218706559, 17326231117678921325668214077168498563134593883851671914433735718213795341567 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS If brackets are interpreted as 90-degree turns, and left bracket is turn left and go forward 1 unit, right bracket is turn right and go forward 1 unit, then a Levy C curve is drawn. LINKS Table of n, a(n) for n=0..7. EXAMPLE For n=3, Von Neumann's 3-element set {0, 1, 2} is { {}, {{}}, {{},{{}}} } 0 01 0011 001 00111 1 binary = a(3) = 9807 MATHEMATICA With[{nmax=8}, Map[FromDigits[#, 2]&, NestList["0"<>StringTake[#, {2, -2}]<>#<>"1"&, "01", nmax]]] (* Paolo Xausa, Nov 20 2023 *) PROG (PARI) a(n) = my(k = 1); for(m = 1, n, k = (k-1)*2^(2^m)+2*k+1); k; \\ Thomas Scheuerle, Nov 21 2023 (Python) from functools import lru_cache @lru_cache(maxsize=None) def A367033(n): return 1-(m:=1<<(2<0 else 1 CROSSREFS Cf. A092124 (bit complement), A333447 (bit reversal), A308187 (individual bits). Sequence in context: A188388 A076628 A198411 * A097421 A180418 A166999 Adjacent sequences: A367030 A367031 A367032 * A367034 A367035 A367036 KEYWORD nonn,base,easy AUTHOR Stuart E Anderson, Nov 20 2023 EXTENSIONS a(7) from Paolo Xausa, Nov 20 2023 Offset corrected by Kevin Ryde, Dec 24 2023 STATUS approved

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Last modified February 23 08:34 EST 2024. Contains 370272 sequences. (Running on oeis4.)