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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A088812 Number of subsets of {1, ..., n} that are neither double-free nor sum-free. 3
0, 0, 0, 1, 2, 6, 21, 49, 119, 266, 626, 1315, 2859, 5878, 12798, 26038, 54485, 109976, 230159, 462634, 945846, 1897597, 3893242, 7798862, 15834340, 31695551, 64315161, 128693477 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

a(n) = 2^n - A088813(n) = A088808(n)-A088811(n) = A088809(n)-A088810(n).

LINKS

Table of n, a(n) for n=0..27.

Eric Weisstein's World of Mathematics, Double-Free Set

Eric Weisstein's World of Mathematics, Sum-Free Set

Reinhard Zumkeller, Illustration of initial terms

CROSSREFS

Sequence in context: A066893 A004192 A104143 * A228398 A228394 A245749

Adjacent sequences:  A088809 A088810 A088811 * A088813 A088814 A088815

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Oct 19 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 16:08 EDT 2019. Contains 322461 sequences. (Running on oeis4.)