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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A291312 Numbers that contain exactly one pair of identical digits x and a triple of identical digits y (x not equal y). 0
10001, 10010, 10011, 10100, 10101, 10110, 11000, 11001, 11010, 11100, 11122, 11133, 11144, 11155, 11166, 11177, 11188, 11199, 11212, 11221, 11222, 11313, 11331, 11333, 11414, 11441, 11444, 11515, 11551, 11555, 11616, 11661, 11666, 11717, 11771, 11777, 11818, 11881, 11888, 11919, 11991, 11999, 12112, 12121, 12122, 12211, 12212, 12221 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Since other digits may be present, the last term is 9998876543210; otherwise the last term would be 99988 (as communicated by Giovanni Resta).

LINKS

Table of n, a(n) for n=1..48.

MATHEMATICA

ok[n_] := Block[{d = DigitCount[n]}, Count[d, 2] == 1 == Count[d, 3] && {} == Select[d, # > 3 &]]; Select[Range[22200], ok] (* Giovanni Resta, Aug 25 2017 *)

CROSSREFS

Sequence in context: A091566 A113758 A273531 * A203591 A115850 A082567

Adjacent sequences:  A291309 A291310 A291311 * A291313 A291314 A291315

KEYWORD

nonn,base,fini

AUTHOR

Enrique Navarrete, Aug 21 2017

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 November 30 22:59 EST 2021. Contains 349426 sequences. (Running on oeis4.)