login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A132183 Number of "regular" Boolean functions of n variables. 0
2, 3, 5, 10, 27, 119, 1173, 44315, 16175190, 284432730176 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

The sequence also counts order ideals (or antichains) of the binary majorization lattice with 2^n points. That lattice for n=5 will be illustrated in Fig. 8 of Volume 4 of The Art of Computer Programming. The basic properties of this lattice will be discussed in exercise 7.1.1-109 of that book. (The material of Section 7.1.1 will be available in paperback in a couple months.)

EXAMPLE

For example, the 10 Boolean functions for n=3 have the truth tables

00000000

00000001

00000011

00000111

00001111

00010111

00011111

00111111

01111111

11111111

(things don't get very interesting until n=4 or 5).

CROSSREFS

Sequence in context: A204518 A088938 A000617 * A003504 A003182 A134294

Adjacent sequences:  A132180 A132181 A132182 * A132184 A132185 A132186

KEYWORD

nonn

AUTHOR

D. E. Knuth, Nov 19 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 12:15 EST 2012. Contains 205909 sequences.