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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A133612 Unique sequence of digits a(0), a(1), a(2), .. such that for all k >= 2, the number A(k) := Sum_{n = 0..k-1 } a(n)*10^n satisfies 2^A(k) == A(k) mod 10^k. 4
6, 3, 7, 8, 4, 9, 2, 3, 4, 3, 5, 3, 5, 7, 0, 5, 1, 6, 8, 9, 0, 8, 3, 3, 3, 5, 8, 9, 5, 1, 0, 0, 6, 2, 7, 8, 6, 9, 6, 8, 2, 5, 5, 4, 1, 0, 7, 5, 4, 2, 6, 8, 2, 6, 1, 4, 8, 2, 8, 2, 1, 2, 1, 2, 1, 9, 0, 7 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

10-adic expansion of the iterated exponential 2^^n for sufficiently large n (where c^^n denotes a tower of c's of height n). E.g. For n>9, 2^^n == 2948736 (mod 10^7)

Sequences A133612-A133619 and A144539-A144544 generalize the observation that 7^343 == 343 mod 1000.

REFERENCES

M. RipĂ , La strana coda della serie n^n^...^n, Trento, UNI Service, Nov 2011. ISBN 978-88-6178-789-6

LINKS

J. Jimenez Urroz and J. Luis A. Yebra, On the equation a^x == x (mod b^n), J. Int. Seq. 12 (2009) #09.8.8

EXAMPLE

2^36 = 68719476736 == 36 (mod 100), 2^736 == 736 (mod 1000), 2^8736 == 8736 (mod 10000), etc.

CROSSREFS

Cf. A133613-A133619 and A144539-A144544.

Sequence in context: A200239 A097676 A125123 * A070392 A115371 A096253

Adjacent sequences:  A133609 A133610 A133611 * A133613 A133614 A133615

KEYWORD

nonn,base

AUTHOR

Daniel Geisler (daniel(AT)danielgeisler.com), Dec 18 2007

EXTENSIONS

Edited by N. J. A. Sloane (njas(AT)research.att.com), Dec 22 2007 and Dec 22 2008

More terms from J. Luis A. Yebra, Dec 12 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 17:13 EST 2012. Contains 205828 sequences.