A210768 Number of bilaterally asymmetric 8-hoops with n symbols and no a-rooted trees.

1, 3, 918, 6669, 33665, 131616, 425866, 1192178, 2977857

Offset: 2

Author

N. J. A. Sloane, Mar 25 2012

Keywords

• nonn

Comments

It appears that table 2 of the Williamson article contains typographical errors and the sequence was intended to read as in A210699.

Links

• Williamson, S. G. The combinatorial analysis of patterns and the principle of inclusion-exclusion. Discrete Math. 1 (1972), no. 4, 357--388. MR0299493 (45 #8541)

Crossrefs

Cf. A210766, A060560, A295925.