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 A276690 Binary Barker codes written in base 10. 1
 2, 3, 6, 13, 14, 29, 114, 1810, 7989 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This is almost certainly the complete list of Barker codes. Codes of the same length which also have similar autocorrelation function are considered as the same and only one code which has greatest value is stored. For example: for codes of length 5 in binary representation: 00010, 01000, 10111 and 11101 only one code 11101 (29 in decimal) should be stored. - Sergiy Piyatakov, Jan 13 2017 LINKS Eric Weisstein's World of Mathematics, Barker Code EXAMPLE 29 (binary: 11101) is in the sequence because + + + - + is a Barker code. PROG (Python) def ok(n):     t = [(-1)**int(x) for x in bin(n)[2:]]     return all(abs(sum(t[i]*t[i+k] for i in range(len(t)-k))) <= 1 for k in range(1, len(t))) def not_dup(n):     b = bin(n)[2:]     i = ''.join('0' if c=='1' else '1' for c in b)     return b >= b[::-1] and b >= i[::-1] a = [n for n in range(2, 2**13) if not_dup(n) and ok(n)] print(a) # Andrey Zabolotskiy, Jan 13 2017 CROSSREFS Cf. A091704. Sequence in context: A187013 A295324 A054049 * A175281 A244790 A111503 Adjacent sequences:  A276687 A276688 A276689 * A276691 A276692 A276693 KEYWORD nonn AUTHOR Gordon Hamilton, Sep 13 2016 EXTENSIONS Corrected by Sergiy Piyatakov, Jan 13 2017 STATUS approved

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Last modified August 12 09:05 EDT 2020. Contains 336438 sequences. (Running on oeis4.)