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

2,2

Comments

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

Links

Table of n, a(n) for n=2..10.

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.

Sequence in context: A167472 A199040 A094592 * A332193 A167058 A167067

Adjacent sequences: A210765 A210766 A210767 * A210769 A210770 A210771

Keyword

nonn

Author

N. J. A. Sloane, Mar 25 2012

Status

approved