A093486 Least k >= 0 such that k! + n is a square, or -1 if no such number exists.

0, 4, 2, 0, -1, -1, -1, 2, 0, 6, 3, -1, 4, -1, 2, 0, -1, -1, -1, 3, -1, -1, -1, 2, 0, 4, -1, -1, -1, -1, 3, -1, -1, -1, 2, 0, -1, -1, -1, -1, 4, -1, -1, 3, -1, -1, -1, 2, 0, 5, -1, -1, -1, -1, -1, -1, -1, 4, 3, -1, -1, -1, 2, 0, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 3, 4, -1, -1, 2, 0, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 3, -1

Offset

1,2

Comments

It is only a guess that a(4)=a(5)=a(6) = -1.

All -1 values are unproved. I have checked all k <= 2000. - David Wasserman, Apr 06 2007

Links

Table of n, a(n) for n=1..96.

Crossrefs

Sequence in context: A107088 A137986 A330768 * A259618 A354681 A115143

Adjacent sequences: A093483 A093484 A093485 * A093487 A093488 A093489

Keyword

less,sign

Author

Amarnath Murthy, Apr 14 2004

Extensions

More terms from David Wasserman, Apr 06 2007

Status

approved