|
| |
|
|
A103300
|
|
Number of perfect rulers with length n (n>=0).
|
|
6
| |
|
|
1, 1, 1, 2, 3, 4, 2, 12, 8, 4, 38, 30, 14, 6, 130, 80, 32, 12, 500, 326, 150, 66, 18, 4, 944, 460, 166, 56, 12, 6, 2036, 890, 304, 120, 20, 10, 2, 2678, 974, 362, 100, 36, 4, 2, 4892, 2114, 684, 238, 68, 22, 4, 16318, 6350, 2286, 836, 330, 108, 24, 12, 31980, 12252
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,4
|
|
|
COMMENTS
| For definitions, references and links related to complete rulers see A103294.
|
|
|
LINKS
| Index entries for sequences related to perfect rulers.
|
|
|
FORMULA
| a(n) = T(n, A103298(n)) where the triangle T is described by A103294.
|
|
|
EXAMPLE
| a(5)=4 counts the perfect rulers with length 5, {[0,1,3,5],[0,2,4,5],[0,1,2,5],[0,3,4,5]}.
|
|
|
CROSSREFS
| Cf. A004137 (Maximal number of edges in a graceful graph on n nodes).
Cf. A103301, A103297, A103298.
Sequence in context: A153038 A117009 A204842 * A141470 A141331 A017889
Adjacent sequences: A103297 A103298 A103299 * A103301 A103302 A103303
|
|
|
KEYWORD
| nonn,nice
|
|
|
AUTHOR
| Peter Luschny (peter(AT)luschny.de) Feb 28 2005
|
| |
|
|
