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A068596
Number of 4-ary Lyndon words whose trace and subtrace are both 0 mod 4.
12
1, 0, 1, 1, 11, 44, 169, 588, 1948, 6560, 23133, 84565, 317755, 1198336, 4509419, 16909184, 63409935, 238609052, 902444517, 3429249843, 13076666409, 49977802752, 191312873561, 733365845820, 2815437297416, 10825960652800, 41694907460224, 160823207301705
OFFSET
1,5
COMMENTS
The trace of a word is the sum of its characters; the subtrace of a word is the sum of all products of pairs of its characters.
KEYWORD
nonn
AUTHOR
Frank Ruskey, Mar 28 2002
EXTENSIONS
Terms a(15) onward from Max Alekseyev, Apr 09 2013
STATUS
approved