login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A091047 a(n) = the final value of n reached through repeated interpretation of n as a base b+1 number where b is the largest digit of n. 2
1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 5, 7, 9, 3, 7, 3, 3, 19, 6, 7, 8, 3, 9, 3, 6, 3, 6, 29, 5, 7, 9, 3, 19, 3, 3, 7, 3, 39, 6, 7, 8, 3, 9, 29, 19, 39, 9, 49, 5, 7, 9, 3, 19, 3, 7, 39, 3, 59, 8, 3, 9, 29, 19, 39, 9, 3, 9, 69, 7, 39, 3, 59, 8, 3, 9, 29, 39, 79, 3, 59, 8, 3, 9, 29, 39, 79, 3, 89, 90, 91, 92 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Any value of n with at least one digit 9 will not reduce further since 9+1 is 10 and n in base 10 is n. Also any single-digit number will likewise not reduce further. Many terms reduce in very few steps and others take longer (88 for example, takes 8 steps). See A091048 for the number of steps for each value of n. There is no maximum number of steps. See A091049 to see the first term requiring n steps.

LINKS

Table of n, a(n) for n=1..92.

C. Seggelin, Interesting Base Conversions.

EXAMPLE

a(18)=3 because 18 in base 9 is 17. 17 in base 8 is 15. 15 in base 6 is 11. 11 in base 2 is 3. 3 does not reduce further because 3 in base 4 is 3. Thus 18 reduces to 3 in 4 steps.

CROSSREFS

Cf. A054055 (largest digit of n) A068505 (n as base b+1 number where b=largest digit of n) A091048 (number of times n must be interpreted as a base b+1 number where b is the largest digit of n until an unchanging value is reached) A091049 (a(n) = first term which reduces to an unchanging value in n steps via repeated interpretation of a(n) as a base b+1 number where b is the largest digit of a(n)).

Sequence in context: A322001 A081594 A038506 * A068505 A080719 A049105

Adjacent sequences:  A091044 A091045 A091046 * A091048 A091049 A091050

KEYWORD

base,nonn

AUTHOR

Chuck Seggelin (barkeep(AT)plastereddragon.com), Dec 15 2003

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 February 17 00:25 EST 2020. Contains 331976 sequences. (Running on oeis4.)