login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A123934 Triangle T(n,k), 1<=k<=n :forms the odd-indexed trinomial coefficients (A027907). 0
1, 2, 2, 3, 7, 3, 4, 16, 16, 4, 5, 30, 51, 30, 5, 6, 50, 126, 126, 50, 6, 7, 77, 266, 393, 266, 77, 7 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..28.

FORMULA

Sum_{k, 1<=k<=n}T(n,k)=A003462(n)=(3^n-1)/2.

EXAMPLE

Triangle begins:

1;

2, 2;

3, 7, 3;

4, 16, 16, 4;

5, 30, 51, 30, 5;

6, 50, 126, 126, 50, 6;

7, 77, 266, 393, 266, 77, 7;

CROSSREFS

Cf. A056241.

Sequence in context: A183442 A296019 A134232 * A208151 A203362 A183407

Adjacent sequences:  A123931 A123932 A123933 * A123935 A123936 A123937

KEYWORD

nonn,tabl

AUTHOR

Philippe Deléham, Oct 30 2006

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 24 12:28 EDT 2021. Contains 347642 sequences. (Running on oeis4.)