A279611 Number of binary palindromes of length 2n+1 having no (7/3)+ powers.

2, 2, 2, 2, 2, 2, 4, 6, 6, 4, 6, 10, 10, 12, 16, 20, 20, 26, 34, 46, 50, 60, 68, 88, 112, 134, 166, 196, 240, 288, 348, 428, 524, 618, 758, 930, 1142, 1384, 1680, 2066, 2516, 3056, 3746, 4562, 5568, 6780, 8254, 10098, 12310, 15042, 18346, 22360, 27332, 33318, 40632, 49702, 60594, 73986

Offset

0,1

Comments

A (7/3)+ power is a word of the form xxx', where x' is a prefix of x and |x'| > |x|/3. Every odd length (2n+1) is guaranteed to have at least one such palindrome.

Links

Table of n, a(n) for n=0..57.

Example

For n = 6 the 4 palindromes avoiding (7/3)+ powers are {0011001001100, 0100110110010, 1011001001101, 1100110110011}.

Crossrefs

Sequence in context: A216452 A307616 A202709 * A008767 A244461 A366811

Adjacent sequences: A279608 A279609 A279610 * A279612 A279613 A279614

Keyword

nonn

Author

Jeffrey Shallit, Dec 15 2016

Status

approved