|
Search: id:A138776
|
|
|
| A138776 |
|
Triangle read by rows: T(n,k)=binomial(n-2k,3k+1) (n>=1, 0<=k<=(n-1)/5). |
|
+0
1
|
|
| 1, 2, 3, 4, 5, 6, 1, 7, 5, 8, 15, 9, 35, 10, 70, 11, 126, 1, 12, 210, 8, 13, 330, 36, 14, 495, 120, 15, 715, 330, 16, 1001, 792, 1, 17, 1365, 1716, 11, 18, 1820, 3432, 66, 19, 2380, 6435, 286, 20, 3060, 11440, 1001
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Row n contains floor((n+4)/5) terms.
Row sums yield A137357.
|
|
REFERENCES
|
D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.1.4.
|
|
MAPLE
|
T:=proc(n, k) options operator, arrow: binomial(n-2*k, 3*k+1) end proc: for n to 20 do seq(T(n, k), k=0..(n-1)*1/5) end do; # yields sequence in triangular form
|
|
CROSSREFS
|
Cf. A137357.
Sequence in context: A104414 A125934 A125935 this_sequence A064830 A160377 A106608
Adjacent sequences: A138773 A138774 A138775 this_sequence A138777 A138778 A138779
|
|
KEYWORD
|
nonn,tabf
|
|
AUTHOR
|
Emeric Deutsch (deutsch(AT)duke.poly.edu), May 10 2008
|
|
|
Search completed in 0.002 seconds
|
