|
| |
|
|
A028326
|
|
Twice Pascal's triangle A007318: T(n,k) = 2*C(n,k).
|
|
8
| |
|
|
2, 2, 2, 2, 4, 2, 2, 6, 6, 2, 2, 8, 12, 8, 2, 2, 10, 20, 20, 10, 2, 2, 12, 30, 40, 30, 12, 2, 2, 14, 42, 70, 70, 42, 14, 2, 2, 16, 56, 112, 140, 112, 56, 16, 2, 2, 18, 72, 168, 252, 252, 168, 72, 18, 2, 2, 20, 90, 240, 420, 504, 420, 240, 90, 20, 2, 2, 22, 110, 330, 660, 924
(list; table; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
COMMENTS
| Also number of binary vectors of length n+1 with k+1 runs (1<=k<=n).
|
|
|
EXAMPLE
| Triangle begins:
2
2, 2
2, 4, 2
2, 6, 6, 2
2, 8, 12, 8, 2
2, 10, 20, 20, 10, 2
2, 12, 30, 40, 30, 12, 2
2, 14, 42, 70, 70, 42, 14, 2
2, 16, 56, 112, 140, 112, 56, 16, 2
2, 18, 72, 168, 252, 252, 168, 72, 18, 2
2, 20, 90, 240, 420, 504, 420, 240, 90, 20, 2
2, 22, 110, 330, 660, 924, 924, 660, 330, 110, 22, 2
2, 24, 132, 440, 990, 1584, 1848, 1584, 990, 440, 132, 24, 2
|
|
|
MAPLE
| T:=proc(n, k) if k=1 then ithprime(k) elif k>n then 0 else T(n-1, k)+T(n-1, k-1) fi end: for n from 1 to 13 do seq(T(n, k), k=1..n) od; - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 16 2006
|
|
|
CROSSREFS
| Cf. A028327, A007318.
Sequence in context: A187467 A081755 A097859 * A156046 A048003 A098219
Adjacent sequences: A028323 A028324 A028325 * A028327 A028328 A028329
|
|
|
KEYWORD
| nonn,tabl,easy,nice
|
|
|
AUTHOR
| Mohammad K. Azarian (ma3(AT)evansville.edu)
|
|
|
EXTENSIONS
| More terms from Donald Manchester, Jr. (s1199170(AT)cedarnet.cedarville.edu)
|
| |
|
|
