

A075464


a(n) is the minimal number of nontrivial switch flippings needed to solve the allones lights out problem on an n X n square.


5



1, 4, 5, 4, 15, 28, 33, 40, 25, 44, 55, 72, 105, 56, 117, 104, 147, 188, 141, 224, 245, 276, 231, 270, 353, 356, 405, 416, 345, 376, 553, 428, 469, 520, 563, 600, 761, 772, 561, 696, 891, 940, 953, 772, 1069, 1188, 971, 1096, 1165, 1220, 1317, 1256, 1487, 1400
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OFFSET

1,2


COMMENTS

For squares having multiple possible solutions (see A075462, A075463), there may be nontrivial solutions involving *more* than this number of flips.


REFERENCES

See A075462 for references.


LINKS

Max Alekseyev and Zhao Hui Du, Table of n, a(n) for n = 1..78 (terms 1..60 from Max Alekseyev)
Eric Weisstein's World of Mathematics, Lights Out Puzzle
Zhao Hui Du, C code for the problem Please compile it by latest gcc with option O3 msse4.2


CROSSREFS

Cf. A075462, A075463.
Sequence in context: A184833 A281385 A279270 * A247858 A247860 A196756
Adjacent sequences: A075461 A075462 A075463 * A075465 A075466 A075467


KEYWORD

nonn,nice


AUTHOR

Eric W. Weisstein, Sep 17 2002


EXTENSIONS

a(26)a(29) from Les Reid, Sep 09 2007
a(30)a(38) from Max Alekseyev, Sep 17 2009
Extended by Max Alekseyev, Sep 20 2009


STATUS

approved



