|
Search: id:A005321
|
|
|
| A005321 |
|
Upper triangular n X n (0,1)-matrices with no empty rows or columns.
(Formerly M1986)
|
|
+0
8
|
|
| 1, 1, 2, 10, 122, 3346, 196082, 23869210, 5939193962, 2992674197026, 3037348468846562, 6189980791404487210, 25285903982959247885402
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
T. L. Greenough, Ph.D. Thesis, Dartmouth, circa 1975 [ from Tom Trotter ].
Andresen, E.; Kjeldsen, K.; On certain subgraphs of a complete transitively directed graph. Discrete Math. 14 (1976), no. 2, 103-119.
|
|
LINKS
|
Index entries for sequences related to binary matrices
|
|
FORMULA
|
Sum_{k=0..n} C(n, k)b(k), where b(0)=1, b(k+1) = (2^(k+1)-1)*b(k)+(-1)^(k+1) [ A005327 ].
G.f.: Sum(x^n*Product((2^i-1)/(1+(2^i-1)*x),i = 1 .. n),n = 0 .. infinity). - Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 10 2008
|
|
CROSSREFS
|
Sequence in context: A060690 A005617 A013038 this_sequence A092645 A144835 A119191
Adjacent sequences: A005318 A005319 A005320 this_sequence A005322 A005323 A005324
|
|
KEYWORD
|
nonn,easy,nice,more
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
Search completed in 0.002 seconds
|
