A068596 Number of 4-ary Lyndon words whose trace and subtrace are both 0 mod 4.

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

Author

Frank Ruskey, Mar 28 2002

Keywords

• nonn

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.

Links

• Max Alekseyev, PARI/GP scripts for miscellaneous math problems
• F. Ruskey, 4-ary Lyndon words with given trace and subtrace

Crossrefs

Cf. A074403, A074404, A074405, A074406, A074407, A074408, A074409, A074410, A074411, A074412, A074413.

Extensions

Terms a(15) onward from Max Alekseyev, Apr 09 2013