A154819 a(n) = floor(zeta(zeta(...zeta(2)...))), where zeta appears n times; zeta is the Riemann zeta function.

1, 2, 1, 2, 1, 3, 1, 10, 1, 1835, 1

Offset

1,2

Comments

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

Links

Vladimir Reshetnikov, Table of n, a(n) for n = 1..12

Example

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

Mathematica

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

Crossrefs

Sequence in context: A137753 A134780 A247379 * A104145 A230981 A123675

Adjacent sequences: A154816 A154817 A154818 * A154820 A154821 A154822

Keyword

nonn

Author

Vladimir Reshetnikov, Jan 15 2009

Status

approved