login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A248838
Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 4 times
2
2, 6, 24, 120, 718, 4994, 39556, 351320, 3456742, 37314126, 438366374, 5567209930, 75995663398, 1109556555434, 17252609166736, 284620418911180, 4965138989585412, 91317809653363376, 1765937111915469414
OFFSET
1,1
COMMENTS
Column 4 of A248842
LINKS
EXAMPLE
Some solutions for n=6
..0....1....1....1....0....0....1....0....0....1....0....1....1....0....1....1
..0....2....2....0....0....2....0....2....2....0....2....1....1....2....0....1
..3....2....2....0....2....2....3....2....0....3....1....0....2....2....1....3
..3....0....3....3....3....2....1....2....0....0....0....4....0....1....0....0
..0....5....0....2....2....1....2....2....4....3....2....0....5....4....1....1
..3....4....5....1....6....5....5....5....6....2....1....1....5....4....0....2
CROSSREFS
Sequence in context: A164872 A226437 A224287 * A364231 A364234 A052398
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 15 2014
STATUS
approved