

A157615


On an n X n board, a(n) is the maximal number of squares covered by a selfavoiding 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
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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^2n+2 for n even, and a(n)=n^22n+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



