login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A047869 Subsets of an 8-element set in order by number of elements in each subset. 1
0, 1, 2, 4, 8, 16, 32, 64, 128, 3, 5, 6, 9, 10, 12, 17, 18, 20, 24, 33, 34, 36, 40, 48, 65, 66, 68, 72, 80, 96, 129, 130, 132, 136, 144, 160, 192, 7, 11, 13, 14, 19, 21, 22, 25, 26, 28, 35, 37, 38, 41, 42, 44, 49, 50, 52, 56, 67, 69, 70, 73, 74, 76, 81, 82, 84, 88, 97, 98, 100 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Subsets are represented by binary vectors.

LINKS

Sean A. Irvine, Table of n, a(n) for n = 1..256

J. Loughry, Efficiently Enumerating the Subsets of a Set

FORMULA

Main diagonal of the array defined by T(0, j) = j+1 for j>=0, T(i, 0) = i+1 for i>=0, T(i, j) = T(i-1, j-1) + T(i-1, j) +  7; a(n) = 2^(n-1)*(n+16) - 7. - Benoit Cloitre, Jun 17 2003

EXAMPLE

The analogous sequences for smaller k are as follows:

for k = 0: 0;

for k = 1: 0, 1;

for k = 2: 0, 1, 2, 3;

for k = 3: 0, 1, 2, 4, 3, 5, 6, 7;

for k = 4: 0, 1, 2, 4, 8, 3, 5, 6, 9, 10, 12, 7, 11, 13, 14, 15;

for k = 5: 0, 1, 2, 4, 8, 16, 3, 5, 6, 9, 10, 12, 17, 18, 20, 24, 7, 11, 13, 14, 19, 21, 22, 25, 26, 28, 15, 23, 27, 29, 30, 31.

CROSSREFS

Cf. A003188.

Sequence in context: A133024 A243085 A060376 * A270201 A016025 A036161

Adjacent sequences:  A047866 A047867 A047868 * A047870 A047871 A047872

KEYWORD

fini,full,nonn

AUTHOR

Joe Loughry (loughry(AT)uswest.net)

EXTENSIONS

Offset corrected by Sean A. Irvine, May 22 2021

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 November 29 06:00 EST 2021. Contains 349416 sequences. (Running on oeis4.)