login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A167684 Triangle read by rows given by [2,-1,1,-2,0,0,0,0,0,0,0,...] DELTA [1,0,1,-1,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938. 0
1, 2, 1, 2, 3, 1, 0, 2, 3, 1, 0, 0, 2, 3, 1, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..104.

FORMULA

G.f.: (1+2*x+2*x^2+x^2*y)/(1-x*y). - Philippe Deléham, Nov 09 2013

T(n,k) = T(n-1,k-1) for n>2, T(0,0) = T(1,1) = T(2,2) = 1, T(1,0) = T(2,0) = 2, T(2,1) = 3, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Nov 09 2013

EXAMPLE

Triangle begins :

1 ;

2,1 ;

2,3,1 ;

0,2,3,1 ;

0,0,2,3,1 ;

0,0,0,2,3,1 ;

0,0,0,0,2,3,1 ; ...

CROSSREFS

Sequence in context: A249777 A289065 A132815 * A094646 A124448 A143343

Adjacent sequences:  A167681 A167682 A167683 * A167685 A167686 A167687

KEYWORD

nonn,tabl

AUTHOR

Philippe Deléham, Nov 09 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 15 11:18 EST 2019. Contains 329144 sequences. (Running on oeis4.)