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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A157615 On an n X n board, a(n) is the maximal number of squares covered by a self-avoiding path made of alternated vertical and horizontal unitary steps. 3
1, 4, 7, 14, 19, 32, 39, 58, 67, 92, 103, 134, 147, 184, 199, 242, 259, 308 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

From an idea of Leroy Quet, discussed on the SeqFan mailing list.

David Wilson conjectures that the formula for a(n) is:

a(1)=1, then, a(n)=n^2-n+2 for n even, and a(n)=n^2-2n+4 for n>1 odd.

LINKS

Table of n, a(n) for n=1..18.

Giovanni Resta, Illustration of initial terms

CROSSREFS

A157616, A157617

Sequence in context: A310920 A161426 A115759 * A188319 A171378 A147478

Adjacent sequences:  A157612 A157613 A157614 * A157616 A157617 A157618

KEYWORD

hard,more,nonn,nice

AUTHOR

Giovanni Resta, Mar 03 2009

EXTENSIONS

a(13)-a(18) computed using integer linear programming by Rob Pratt, Apr 07 2015

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 21 16:04 EST 2019. Contains 329371 sequences. (Running on oeis4.)