|
Search: id:A002501
|
|
|
| A002501 |
|
7^n-3*4^n+2*3^n.
(Formerly M5078 N2197)
|
|
+0
14
|
|
| 1, 19, 205, 1795, 14221, 106819, 778765, 5581315, 39606541, 279447619, 1965098125, 13792018435, 96690872461, 677427332419, 4744368982285, 33220131761155, 232579232659981, 1628208214321219, 11398072876175245
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Counts connected relations.
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
G. Kreweras, Inversion des polynomes de Bell bidimensionnels et application au denombrement des relations binaires connexes. C. R. Acad. Sci. Paris Ser. A-B 268 1969 A577-A579.
|
|
CROSSREFS
|
Cf. A005333, A001047, A002502, A093732, A093733.
Sequence in context: A113596 A155670 A085770 this_sequence A125407 A023017 A022647
Adjacent sequences: A002498 A002499 A002500 this_sequence A002502 A002503 A002504
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
EXTENSIONS
|
Better definition and more terms from Goran Kilibarda, Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 14 2004
|
|
|
Search completed in 0.002 seconds
|
