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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A214532 List of words over {1,9} with equal numbers of 1's and 9's. 0
19, 91, 1199, 1919, 1991, 9119, 9191, 9911, 111999, 119199, 119919, 119991, 191199, 191919, 191991, 199119, 199191, 199911, 911199, 911919, 911991, 919119, 919191, 919911, 991119, 991191, 991911, 999111, 11119999, 11191999 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is to 9 as A214531 is to 8, as A214530 is to 7, as A214530 is to 6, as A214522 is to 5, as A214521 is to 4, as A214488 is to 3, and as A214218 is to 2.

The subsequence of primes (when interpreted as decimal integers) is A087515.

LINKS

Table of n, a(n) for n=1..30.

MATHEMATICA

FromDigits/@(Flatten[Permutations/@Table[Join[Table[1, {n}], Table[9, {n}]], {n, 4}], 1]) (* Harvey P. Dale, Aug 20 2014 *)

CROSSREFS

Cf. A214218, A214488, A214521, A214522, A214524, A214530, A214531.

Sequence in context: A043232 A044012 A288485 * A118294 A157098 A037238

Adjacent sequences:  A214529 A214530 A214531 * A214533 A214534 A214535

KEYWORD

nonn,base,easy

AUTHOR

Jonathan Vos Post, Jul 20 2012

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 October 23 03:21 EDT 2018. Contains 316519 sequences. (Running on oeis4.)