|
| |
|
|
A027805
|
|
21*(n+1)*C(n+4,9).
|
|
0
| |
|
|
126, 1470, 9240, 41580, 150150, 462462, 1261260, 3123120, 7147140, 15315300, 31039008, 59961720, 111105540, 198470580, 343219800, 576609264, 943854450, 1509157650, 2362159800, 3626122500, 5468192730
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 5,1
|
|
|
COMMENTS
| Number of 14-subsequences of [ 1, n ] with just 4 contiguous pairs.
|
|
|
LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (11,-55,165,-330,462,-462,330,-165,55,-11,1).
|
|
|
FORMULA
| G.f. 42*(3+2x)/(1-x)^11
C(n+6, 6)*C(n+9, 4) - Zerinvary Lajos (zlaja(AT)freemail.hu), May 25 2005
|
|
|
MATHEMATICA
| Table[21(n+1)Binomial[n+4, 9], {n, 5, 30}] (* From Harvey P. Dale, Sep 19 2011 *)
|
|
|
PROG
| (PARI) a(n)=21*(n+1)*binomial(n+4, 9) \\ Charles R Greathouse IV, Sep 19 2011
|
|
|
CROSSREFS
| Sequence in context: A172139 A194717 A002953 * A027814 A109146 A189345
Adjacent sequences: A027802 A027803 A027804 * A027806 A027807 A027808
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| thi ngoc dinh (via rkg(AT)cpsc.ucalgary.ca)
|
| |
|
|
