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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A112883 A skew Jacobsthal-Pascal matrix. 1
1, 0, 1, 0, 1, 3, 0, 0, 2, 5, 0, 0, 1, 7, 11, 0, 0, 0, 3, 16, 21, 0, 0, 0, 1, 12, 41, 43, 0, 0, 0, 0, 4, 34, 94, 85, 0, 0, 0, 0, 1, 18, 99, 219, 171, 0, 0, 0, 0, 0, 5, 60, 261, 492, 341, 0, 0, 0, 0, 0, 1, 25, 195, 678, 1101, 683, 0, 0, 0, 0, 0, 0, 6, 95, 576, 1692, 2426, 1365, 0, 0, 0, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

T(n,n) is A001045(n), row sums are A006130, column sums are A002605. Compare with [0,1,-1,0,0,..] DELTA [1,2,-2,0,0,...] where DELTA is the operator defined in A084938. A skewed version of the Riordan array (1/(1-x-2x^2),x/(1-x-2x^2)) (A073370).

Modulo 2, this sequence gives A106344 . [From Philippe Deléham, Dec 18 2008]

LINKS

Table of n, a(n) for n=0..82.

FORMULA

G.f.: 1/(1-yx(1-x)-2x^2*y*2); Number triangle T(n, k)=sum{j=0..2k-n, C(n-k+j, n-k)C(j, 2k-n-j)2^(2k-n-j)}; T(n, k)=A073370(k, n-k); T(n, k) = T(n-1, k-1) + T(n-2, k-1) +2*T(n-2, k-2) (Philippe Deleham).

EXAMPLE

Rows begin

1;

0, 1;

0, 1, 3;

0, 0, 2, 5;

0, 0, 1, 7, 11;

0, 0, 0, 3, 16, 21;

0, 0, 0, 1, 12, 41, 43;

0, 0, 0, 0, 4, 34, 94, 85;

0, 0, 0, 0, 1, 18, 99, 219, 171;

0, 0, 0, 0, 0, 5, 60, 261, 492, 341;

0, 0, 0, 0, 0, 1, 25, 195, 678, 1101, 683;

CROSSREFS

Cf. A111006.

Sequence in context: A108930 A059682 A156548 * A117138 A292255 A095104

Adjacent sequences:  A112880 A112881 A112882 * A112884 A112885 A112886

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Oct 05 2005

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 September 22 17:13 EDT 2019. Contains 327311 sequences. (Running on oeis4.)