A069783 - OEIS

A069783

a(n) = gcd(d(n!^3), d(n!)) = A069780(n!), where d() is the number of divisors function.

%I #10 Oct 26 2019 20:52:32

%S 1,2,4,8,16,2,4,32,32,10,20,8,16,32,448,448,1792,32,64,80,3200,1280,

%T 2560,320,448,1792,25088,101920,203840,128,256,4096,81920,112640,2048,

%U 8960,17920,1024,2048,5120,10240,5734400,11468800,1003520,250880,8960,17920

%N a(n) = gcd(d(n!^3), d(n!)) = A069780(n!), where d() is the number of divisors function.

%t Table[GCD[DivisorSigma[0, (n!)^3], DivisorSigma[0, n! ]], {n, 1, 100}]

%Y Cf. A000005, A000142, A069780, A069781, A069782.

%K easy,nonn

%O 1,2

%A _Labos Elemer_, Apr 08 2002