A185378 - OEIS

A185378

Number of binary necklaces of 2n beads that are identical when turned over yet cannot be cut to produce a palindrome.

1, 3, 6, 15, 28, 62, 120, 255, 496, 1020, 2016, 4094, 8128, 16376

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OFFSET

1,2

COMMENTS

These necklaces have bilateral symmetry across axes that involve only vertices. a(n) = A029744(2n) - A185333(2n). Conjecture: a(n) = 2^n - 2^((n - 2^t)/(2^(t+1))), where t = number of factors of 2 in n.

LINKS

Table of n, a(n) for n=1..14.

CROSSREFS

Sequence in context: A069712 A076971 A103529 * A285563 A285543 A318396

Adjacent sequences: A185375 A185376 A185377 * A185379 A185380 A185381

KEYWORD

nonn

AUTHOR

Tony Bartoletti, Feb 20 2011

STATUS

approved