login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A241293 Decimal expansion of 4^(4^(4^4)) = 4^^4. 11
2, 3, 6, 1, 0, 2, 2, 6, 7, 1, 4, 5, 9, 7, 3, 1, 3, 2, 0, 6, 8, 7, 7, 0, 2, 7, 4, 9, 7, 7, 8, 1, 7, 9, 4, 3, 0, 9, 4, 6, 1, 2, 7, 2, 9, 1, 4, 7, 7, 5, 1, 5, 4, 4, 6, 7, 1, 9, 2, 5, 6, 9, 4, 6, 2, 1, 2, 7, 1, 1, 8, 5, 3, 6, 6, 6, 4, 7, 5, 5, 2, 4, 9, 4, 5, 7, 6, 9, 3, 5, 0, 1, 0, 1, 9, 4, 1, 9, 9, 7, 7, 1, 6, 1, 6 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The offset is 1 because the true offset would be 8.072304726...*10^153, which is too large to be represented properly in the OEIS.

This is the decimal expansion of 2^2^513. - Jianing Song, Dec 25 2018

LINKS

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

Robert P. Munafo, Hyper4 Iterated Exponential Function..

FORMULA

4^(4^(4^4)) = ((((( ... 245 ... (((((4^4)^4)^4)^4)^4) ... 245 ... ^4)^4)^4)^4)^4)^4.

EXAMPLE

2361022671459731320687702749778179430946127291477515446719256946212711853666475524945769350101941997...(8.072304726...*10^153)...7470426497333490366540651560537534642789067586985427238232605843019607448189676936860456095261392896.

The above line shows the first one hundred decimal digits and the last one hundred digits with the number of unrepresented digits in parenthesis.

The final one hundred digits where computed by: PowerMod[4, 4^4^4, 10^100].

MATHEMATICA

nbrdgt = 105; f[base_, exp_] := RealDigits[ 10^FractionalPart[ N[ exp*Log10[ base], nbrdgt + Floor[ Log10[ exp]] + 2]], 10, nbrdgt][[1]]; f[ 4, 4^4^4] (* or *)

p = 4; f[n_] := Quotient[n^p, 10^(Floor[p * Log10@ n] - (1004 + p^p))]; IntegerDigits@ Quotient[ Nest[ f@ # &, p, p^p], 10^(900 + p^p)] (* Program fixed by Jianing Song, Sep 18 2019 *)

CROSSREFS

Cf. A114561, A085667, A202955, A054382, A014221, A241291, A241292, A241294, A241295, A241296, A241297, A241298, A241299, A243913.

Sequence in context: A082052 A232930 A217100 * A107409 A268603 A226871

Adjacent sequences:  A241290 A241291 A241292 * A241294 A241295 A241296

KEYWORD

nonn,cons,fini

AUTHOR

Robert Munafo and Robert G. Wilson v, Apr 18 2014

EXTENSIONS

Keyword: fini added by Jianing Song, Sep 18 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 13 06:26 EST 2019. Contains 329968 sequences. (Running on oeis4.)