A154819 - OEIS

%I #11 Apr 16 2022 15:00:38

%S 1,2,1,2,1,3,1,10,1,1835,1

%N a(n) = floor(zeta(zeta(...zeta(2)...))), where zeta appears n times; zeta is the Riemann zeta function.

%C a(n)=1 for odd n; a(12) (see the b-file) is too large to display here.

%H Vladimir Reshetnikov, <a href="/A154819/b154819.txt">Table of n, a(n) for n = 1..12</a>

%e a(1) = floor(zeta(2)); a(2) = floor(zeta(zeta(2)));

%t Block[{$MaxExtraPrecision = Infinity}, Table[Floor[Nest[Zeta, 2, n]], {n, 1, 12}]]

%K nonn

%O 1,2

%A _Vladimir Reshetnikov_, Jan 15 2009