A081991 Numbers in ascending order formed by using all the digits of the next n numbers.

1, 23, 32, 456, 465, 546, 564, 645, 654, 10789, 10798, 10879, 10897, 10978, 10987, 17089, 17098, 17809, 17890, 17908, 17980, 18079, 18097, 18709, 18790, 18907, 18970, 19078, 19087, 19708, 19780, 19807, 19870, 70189, 70198, 70819, 70891

Offset

1,2

Comments

The next four numbers are 7,8,9 and 10 and hence the next terms are all the numbers formed by the digits 1,0,7,8 and 9 in ascending order.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..5000

Example

The next two numbers are 2 and 3 and the two numbers that can be formed are 23 and 32 hence a(2) = 23 and a(3) = 32.

Mathematica

uad[l_]:=Module[{d=Flatten[IntegerDigits/@l], len}, len=Length[d]; Select[FromDigits/@ Permutations[ d], IntegerLength[#]==len&]//Sort]; uad/@With[{nn=4}, TakeList[Range[ (nn(nn+1))/2], Range[nn]]]//Flatten (* Harvey P. Dale, Jan 01 2024 *)

Crossrefs

Cf. A081992, A081993.

Sequence in context: A039410 A043233 A044013 * A118298 A209247 A076091

Adjacent sequences: A081988 A081989 A081990 * A081992 A081993 A081994

Keyword

base,nonn

Author

Amarnath Murthy, Apr 05 2003

Extensions

More terms from David Wasserman, Jul 27 2004

Status

approved