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

Offset: 1

Author

Tony Bartoletti, Feb 20 2011

Keywords

• nonn

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.