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A279625 Number of ternary palindromes of length 2n+1 having no (7/4)+ powers. 1

%I

%S 3,6,6,12,12,6,6,6,6,6,12,12,18,30,30,36,54,66,72,90,96,114,168,210,

%T 252,330,414,486,618,756,888,1200,1494,1776,2232,2796,3456,4362,5454,

%U 6660,8454,10530,12924,16116,20232,25272,31446,39150,48408,60438

%N Number of ternary palindromes of length 2n+1 having no (7/4)+ powers.

%C A (7/4)+ power is a word of the form xx', where x' is a prefix of x and |x'| > (3/4)|x|. Every odd length (2n+1) is guaranteed to have at least one such palindrome.

%e For n = 7 there are 6 palindromes of length 15 satisfying the conditions: {010201202102010, 020102101201020, 101210212012101, 121012010210121, 202120121021202, 212021020120212}.

%Y Cf. A279611.

%K nonn

%O 0,1

%A _Jeffrey Shallit_, Dec 16 2016

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Last modified April 20 22:22 EDT 2019. Contains 322310 sequences. (Running on oeis4.)