1,4

Table of n, a(n) for n=1..84.

a(n) = (floor(sqrt(n)))! mod n.

a(17) = (floor(sqrt(17)))! mod 17 = (floor(4.12...))! mod 17 = 4! mod 17 = 24 mod 17 = 7.

(MAGMA) [ Factorial(Floor(Sqrt(n))) mod n: n in [1..84] ];

Cf. A000142 (factorial numbers), A000196 (integer part of square root of n).

Sequence in context: A221838 A338869 A104588 * A214080 A278241 A010671

Adjacent sequences: A157276 A157277 A157278 * A157280 A157281 A157282

nonn

Thomas Kerscher (Thomas.Kerscher(AT)web.de), Feb 26 2009

Edited and a(1) corrected by Klaus Brockhaus, May 27 2009

approved