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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A121386 Number of different colorings of {1,...,n} that minimize the number of three-term arithmetic progressions that such a coloring can contain. 1
2, 4, 6, 10, 14, 20, 16, 6, 36, 8, 44, 10, 8, 30, 16, 8, 12, 2, 12, 28, 64, 110, 96, 134, 56, 44, 16, 2, 16, 74, 116, 188, 200, 180 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The unique (up to switching colors) sequences for n=18 and n=28 are 001001111000011011 and 0001100011111100000011100111 respectively.

EXAMPLE

a(3)=6 because all non-monochromatic colorings are such an example

CROSSREFS

Cf. A121385.

Sequence in context: A024204 A036641 A062425 * A007777 A082379 A167379

Adjacent sequences:  A121383 A121384 A121385 * A121387 A121388 A121389

KEYWORD

nonn

AUTHOR

Steve Butler (sbutler(AT)math.ucsd.edu), Jul 26 2006

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 17 18:41 EST 2012. Contains 206074 sequences.