login
a(n) = floor(n!/sigma(n)).
1

%I #21 Sep 08 2022 08:45:03

%S 1,0,1,3,20,60,630,2688,27913,201600,3326400,17107200,444787200,

%T 3632428800,54486432000,674928706064,19760412672000,164163428352000,

%U 6082255020441600,57926238289920000,1596591942865920000,31222242438266880000,1077167364120207360000,10340806695553990656000

%N a(n) = floor(n!/sigma(n)).

%H Harry J. Smith, <a href="/A062359/b062359.txt">Table of n, a(n) for n = 1..100</a>

%e a(7) = 630 because floor(7!/sigma(7)) = floor(5040/8) = floor(630) = 630.

%p with(numtheory): seq(floor(factorial(n)/sigma(n)),n=1..25); # _Muniru A Asiru_, Jun 29 2018

%t Table[Floor[n!/DivisorSigma[1,n]],{n,25}] (* _Harvey P. Dale_, Mar 23 2011 *)

%o (PARI) a(n)=n!\sigma(n);

%o (Magma) [Floor(Factorial(n)/DivisorSigma(1, n)): n in [1..25]]; // _Vincenzo Librandi_, Jun 29 2018

%o (GAP) List([1..25],n->Int(Factorial(n)/Sigma(n))); # _Muniru A Asiru_, Jun 29 2018

%K easy,nonn

%O 1,4

%A _Jason Earls_, Jul 06 2001