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A280910
Characteristic sequence of A277238.
1
0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
0
PROG
(PARI) A280910(n) = if(n<=1, n, my(b = binary(n)); if ((#b % 2) && (b[#b\2+1] == 0), return (0)); vecmin(vector(#b\2, k, bitxor(b[k], b[#b-k+1]))) == 1); \\ Antti Karttunen, Dec 23 2018, after isok function given in A277238 by Michel Marcus, Oct 07 2016
CROSSREFS
Cf. A277238.
Sequence in context: A316341 A284901 A071981 * A305816 A359820 A241979
KEYWORD
nonn
AUTHOR
Taylor J. Smith, Jan 10 2017
EXTENSIONS
Term a(0) = 0 prepended and more terms added by Antti Karttunen, Dec 23 2018
STATUS
approved