Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A110180
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A110180 Triangle of generalized central trinomial coefficients. +0
3
1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 7, 5, 1, 1, 1, 19, 13, 7, 1, 1, 1, 51, 49, 19, 9, 1, 1, 1, 141, 161, 91, 25, 11, 1, 1, 1, 393, 581, 331, 145, 31, 13, 1, 1, 1, 1107, 2045, 1441, 561, 211, 37, 15, 1, 1, 1, 3139, 7393, 5797, 2841, 851, 289, 43, 17, 1, 1 (list; table; graph; listen)
OFFSET

0,8

COMMENT

Rows sums are A110181. Diagonal sums are A110182. Columns include central trinomial coefficients A002426, A084601, A084603, A084605, A098264. T(n,k)=central coefficient (1+x+kx^2)^n.

FORMULA

Number triangle T(n, k)=sum{j=0..floor((n-k)/2), C(n-k, j)C(n-k-j, j)k^j}

EXAMPLE

Rows begin

1;

1,1;

1,1,1;

1,3,1,1;

1,7,5,1,1;

1,19,13,7,1,1;

CROSSREFS

Sequence in context: A140670 A068845 A081297 this_sequence A005765 A080214 A096066

Adjacent sequences: A110177 A110178 A110179 this_sequence A110181 A110182 A110183

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jul 14 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 August 29 17:54 EDT 2008. Contains 143238 sequences.


AT&T Labs Research