A131637 - OEIS

%I #10 Nov 23 2019 04:04:51

%S 1,1,1,4,8,24,168,876,1056,11232,92760,180944,4010832,27644436,

%T 93648672,1101958000,10436655840,27621623160,584607107256,

%U 5792507548200,21804094801440,316556065451520,2811301938708480,21826781430144768,297303503947693536,4153310734233341952

%N a(n) = Phi(Bell(n)).

%H Amiram Eldar, <a href="/A131637/b131637.txt">Table of n, a(n) for n = 0..104</a>

%p with(numtheory):with(combinat):a:=n->phi(bell(n)): seq(a(n), n=0..25);

%t Table[EulerPhi[BellB[n]], {n, 0, 25}] (* _Amiram Eldar_, Nov 23 2019 *)

%K nonn

%O 0,4

%A _Zerinvary Lajos_, Oct 02 2007

%E a(24)-a(25) from _Amiram Eldar_, Nov 23 2019