A326660 - OEIS

%I #20 Sep 16 2019 04:10:02

%S 0,0,1,3,12,34,111,315,933,2622,7503,21033,59472,167118,472120,

%T 1332945,3777600,10720869,30516447,87032994,248820704,712743768,

%U 2045784183,5882367570,16942974048,48876558318,141204944529,408494941773,1183247473872,3431450670601

%N Number of n-bead asymmetric bracelets with exactly 3 different colored beads.

%C Asymmetric bracelets are those primitive (period n) bracelets that when turned over are different from themselves.

%H Andrew Howroyd, <a href="/A326660/b326660.txt">Table of n, a(n) for n = 1..200</a>

%F a(n) = A032240(n) - 3*A032239(n) for n >= 3.

%F Moebius transform of A305542.

%e Case n = 4: There are 3 distinct asymmetric bracelets with exactly 3 colors which are aabc, abbc, abcc.

%Y Column k=3 of A309651.

%Y Cf. A032239, A032240, A056343, A056349, A305542, A326789.

%K nonn

%O 1,4

%A _Andrew Howroyd_, Sep 12 2019