A291312 Numbers that contain exactly one pair of identical digits x and a triple of identical digits y (x not equal y).

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

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