OFFSET
1,2
FORMULA
If n is prime then a(n) = n; otherwise, if n <> 4 then a(n) = n^2. - Zak Seidov, Dec 28 2009
a(n) = n!/A092043(n). - Johannes W. Meijer, Jun 04 2016
a(n) = n^2 / n^c(n), where c = A010051 for n >= 5. - Wesley Ivan Hurt, Nov 10 2023
MAPLE
GCDWITHFACTORIAL:=proc(a) local b, i, k:
if whattype(a) <> list then RETURN([]); fi:
b:=[]:
for i to nops(a) do b:=[op(b), gcd(a[i], i!)]: od;
RETURN(b);
end:
MATHEMATICA
Table[GCD[n^2, n!], {n, 54}] (* Michael De Vlieger, Jun 05 2016 *)
PROG
(PARI) a(n)=if(isprime(n), n, if(n==4, 8, n^2)) \\ Charles R Greathouse IV, Feb 01 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Dec 27 2009
STATUS
approved