A007411 Number of matrices with n columns whose rows do not cover each other. Also antichain covers of an unlabeled n-set. (Formerly M3558)

1, 4, 19, 179, 16142, 489996794, 1392195548399980209, 789204635842035039135545297410259321

Offset

2,2

References

V. Jovovic and G. Kilibarda, On enumeration of the class of all monotone Boolean functions, in preparation.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=2..9.

M. Hofri, Email to N. J. A. Sloane, May 1994.

V. Jovovic and G. Kilibarda, On the number of Boolean functions in the Post classes F^{mu}_8, in Russian, Diskretnaya Matematika, 11 (1999), no. 4, 127-138.

V. Jovovic and G. Kilibarda, On the number of Boolean functions in the Post classes F^{mu}_8, English translation, in Discrete Mathematics and Applications, 9, (1999), no. 6, 593-605.

Formula

a(n) = A003182(n) - A003182(n-1) - 1 = A006602(n) - 1.

Crossrefs

Cf. A037843, A006126, A003182, A006602.

Sequence in context: A366699 A292167 A126147 * A356287 A377004 A276259

Adjacent sequences: A007408 A007409 A007410 * A007412 A007413 A007414

Keyword

nonn,hard,more

Author

Micha Hofri (hofri(AT)cs.rice.edu)

Extensions

a(7) from A003182. - N. J. A. Sloane, Aug 13 2015

a(8) from A003182. - Bartlomiej Pawelski, Nov 27 2022

a(9) from A003182. - Dmitry I. Ignatov, Nov 27 2023

Status

approved