A123448 Number of permutation perfect graphs on n nodes.

1, 2, 4, 11, 33, 142, 776, 5699, 50723, 524572, 6037518, 75912033, 1029974969, 14974215412

Offset

1,2

Comments

All permutation graphs are perfect. - Jakub Jablonski, Sep 07 2020

Links

Table of n, a(n) for n=1..14.

S. Hougardy, Home Page

S. Hougardy, Classes of perfect graphs, Discr. Math. 306 (2006), 2529-2571.

Crossrefs

Sequence in context: A123468 A123415 A123469 * A039707 A005470 A123471

Adjacent sequences: A123445 A123446 A123447 * A123449 A123450 A123451

Keyword

nonn,more,hard

Author

N. J. A. Sloane, Oct 18 2006

Extensions

a(11) from Jakub Jablonski, Sep 07 2020

a(12)-a(14) from Tom Johnston, Oct 25 2020

Status

approved