A165740 Positive integers n such that solution to the toric n X n "Lights Out" puzzle is not unique (up to the order of flippings; each flipping appears at most once).

3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 21, 24, 25, 27, 30, 31, 33, 34, 35, 36, 39, 40, 42, 45, 48, 50, 51, 54, 55, 57, 60, 62, 63, 65, 66, 68, 69, 70, 72, 75, 78, 80, 81, 84, 85, 87, 90, 93, 95, 96, 99, 100, 102, 105, 108, 110, 111, 114, 115, 117, 119, 120, 123, 124, 125, 126

Offset: 1

Author

Max Alekseyev, Sep 25 2009

Keywords

• nonn

Comments

Complement to the sequence A165741 in the set of positive integers.

Any positive multiple of a member of this sequence is also a member. Primitive elements are in A007802. - Thomas Buchholz, May 23 2014

References

• See A165738 for the references.

Links

• Max Alekseyev and Thomas Buchholz, Table of n, a(n) for n = 1..1000 [terms 67 through 1000 were computed by Thomas Buchholz, May 20 2014]

Crossrefs

Cf. A159257, A075462, A117870, A165741, A007802, A165738.

Formula

A number n is in this sequence iff A165738(n) > 0.

Extensions

More terms from Thomas Buchholz, May 20 2014