A140663 Decimal expansion of the number x defined by x^(x^x) = 27.

2, 0, 7, 1, 9, 6, 9, 2, 2, 9, 0, 8, 2, 3, 1, 2, 9, 1, 5, 2, 3, 4, 1, 9, 0, 5, 5, 6, 3, 6, 3, 2, 9, 5, 7, 7, 7, 8, 5, 3, 5, 3, 3, 8, 0, 7, 5, 9, 5, 4, 1, 1, 6, 2, 2, 7, 1, 7, 4, 9, 0, 8, 1, 8, 3, 9, 4, 6, 6, 6, 1, 0, 9, 8, 5, 2, 7, 7, 3, 4, 0, 0, 6, 9, 0, 0, 6, 6, 5, 7, 7, 5, 4, 6, 3, 0, 9, 8, 5, 3, 8, 5, 4, 6, 2

Offset

1,1

Links

Table of n, a(n) for n=1..105.

Example

2.07196922908231...

Maple

Digits := 120: x := 2.071 : for i from 1 to 30 do xxx := x^(x^x) : n := xxx-27 : d := xxx*(x^x*log(x)*(1+log(x))+x^(x-1)) ; x := evalf(x-n/d) ; print(x) ; od: # R. J. Mathar, Aug 08 2008

Mathematica

digits = 105; x0 = x /. FindRoot[x^(x^x) == 27, {x, 2}, WorkingPrecision -> digits+1]; RealDigits[x0, 10, digits][[1]] (* Jean-François Alcover, Jan 28 2014 *)

Crossrefs

Cf. A093590.

Sequence in context: A174968 A254445 A346670 * A198108 A300704 A300702

Adjacent sequences: A140660 A140661 A140662 * A140664 A140665 A140666

Keyword

cons,nonn

Author

Joshua Taylor, Jul 11 2008

Extensions

Extended beyond 15 digits by R. J. Mathar, Aug 08 2008

Status

approved