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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A033296 Number of paths from (0,0) to (3n,0) that stay in first quadrant (but may touch horizontal axis), where each step is (2,1),(1,2) or (1,-1) and start with (1,2). 1
1, 6, 42, 326, 2706, 23526, 211546, 1951494, 18366882, 175674054, 1702686090, 16686795846, 165079509042, 1646340228006, 16534463822010, 167081444125702, 1697551974416706, 17330661859937670, 177699201786231530 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..19.

FORMULA

z A^3, where A is the g. f. of A027307. Also: difference of A027307 and A032349.

CROSSREFS

Cf. A027307, A032349.

Sequence in context: A107266 A142985 A118351 * A218755 A165314 A082302

Adjacent sequences:  A033293 A033294 A033295 * A033297 A033298 A033299

KEYWORD

nonn

AUTHOR

Emeric Deutsch

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 July 17 14:44 EDT 2019. Contains 325106 sequences. (Running on oeis4.)