2,2

Table of n, a(n) for n=2..15.

a(3)=12 because the difference between (3!)^2=36 and the next smaller factorial 4!=24 is 12.

Cf. A121347 [Largest number k such that (n!)^2-k!>0].

Sequence in context: A322556 A295413 A202799 * A239365 A277262 A226358

Adjacent sequences: A121345 A121346 A121347 * A121349 A121350 A121351

nonn

Hugo Pfoertner, Aug 15 2006

approved