Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A106351
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A106351 Triangle read by rows: T(n,k) = number of compositions of n into k parts such that no two adjacent parts are equal. +0
6
1, 1, 0, 1, 2, 0, 1, 2, 1, 0, 1, 4, 2, 0, 0, 1, 4, 7, 2, 0, 0, 1, 6, 9, 6, 1, 0, 0, 1, 6, 15, 14, 3, 0, 0, 0, 1, 8, 21, 24, 15, 2, 0, 0, 0, 1, 8, 28, 46, 30, 10, 1, 0, 0, 0, 1, 10, 35, 66, 68, 30, 4, 0, 0, 0, 0, 1, 10, 46, 100, 119, 76, 24, 2, 0, 0, 0, 0, 1, 12, 54, 138, 204, 168, 69, 14, 1, 0, 0 (list; table; graph; listen)
OFFSET

1,5

LINKS

A. Knopfmacher and H. Prodinger, On Carlitz compositions, European Journal of Combinatorics, Vol. 19, 1998, pp. 579-589.

FORMULA

G.f. 1/(1 - sum(k>0, (-1)^(k+1)*x^k*y^k/(1-x^k)).

EXAMPLE

1; 1,0; 1,2,0; 1,2,1,0; 1,4,2,0,0; ...

T(6,3)=7 because the compositions of 6 into 3 parts with no adjacent equal parts are 3+2+1, 3+1+2, 2+3+1, 2+1+3, 1+3+2, 1+2+3, 1+4+1.

CROSSREFS

Row sums: A003242. Columns 3-6: A106352-A106355.

Sequence in context: A136266 A054523 A161363 this_sequence A096800 A036586 A092928

Adjacent sequences: A106348 A106349 A106350 this_sequence A106352 A106353 A106354

KEYWORD

nonn,tabl

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Apr 29 2005

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 20 16:54 EST 2009. Contains 171081 sequences.


AT&T Labs Research