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

 

Logo

"Email this user" was broken Aug 14 to 9am Aug 16. If you sent someone a message in this period, please send it again.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A188380 Balanced ternary Keith numbers. 1
3, 49, 73, 88, 97, 198, 840, 1479, 2425, 5277, 18799 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Only terms in common with base 3 Keith numbers (A188195) for the range examined are 3 and 840.

If the sum of balanced ternary digits of a positive number is 0 or less, then the recurrence from the digits soon becomes consistently negative and the number in question is not a Keith number in balanced ternary.

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

The number 49 in balanced ternary is {1, -1, -1, 1, 1}. The pentanacci-like sequence continues 1, 1, 3, 7, 13, 25, 49, thus 49 is a Keith number in balanced ternary.

MATHEMATICA

(* First run program at A065363 to define balTernDigits *) keithFromListQ[n_Integer, digits_List] := Module[{seq = digits, curr = digits[[-1]], ord = Length[digits]}, While[curr < n, curr = Plus@@Take[seq, -ord]; AppendTo[seq, curr]]; Return[seq[[-1]] == n]]; Select[Range[3, 19683], Plus@@balTernDigits[#] > 0 && keithFromListQ[#, balTernDigits[#]] &]

CROSSREFS

Sequence in context: A094045 A033494 A079837 * A252171 A160763 A041523

Adjacent sequences:  A188377 A188378 A188379 * A188381 A188382 A188383

KEYWORD

nonn,base

AUTHOR

Alonso del Arte, Mar 29 2011

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified August 16 19:56 EDT 2017. Contains 290627 sequences.