The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A236753 Number of simple (non-intersecting) directed paths on the grid graph P_n X P_n. 2
 1, 28, 653, 28512, 3060417, 873239772, 687430009069, 1532025110398168, 9829526954625359697, 183563561823425961932572, 10056737067604248527218979485, 1626248896102138091401810358337184 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This is the number of directed paths on P_n X P_n of any length and also includes one zero length path per vertex. - Andrew Howroyd, May 27 2017 LINKS FORMULA a(n) = 2*A288032(n) + n^2. - Andrew Howroyd, Jun 10 2017 EXAMPLE For n=2 there are 4 zero length paths (one for each vertex), 8 paths with 1 one edge, 8 paths with 2 edges and 8 paths with 3 edges, so a(2)=28. - Andrew Howroyd, May 27 2017 CROSSREFS Cf. A236690 (includes diagonal edges). Cf. A288032, A007764, A121785, A120443. Sequence in context: A184329 A070310 A309804 * A269473 A278805 A160141 Adjacent sequences: A236750 A236751 A236752 * A236754 A236755 A236756 KEYWORD nonn,hard,more AUTHOR Jaimal Ichharam, Jan 30 2014 EXTENSIONS a(6) corrected and a(8) added from Jaimal Ichharam, Feb 13 2014 a(6)-a(8) corrected and a(9)-a(12) from Andrew Howroyd, May 27 2017 STATUS approved

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

Last modified March 24 04:28 EDT 2023. Contains 361454 sequences. (Running on oeis4.)