A138142 Nonnegative numbers with digits in descending order that differ exactly by 1.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 21, 32, 43, 54, 65, 76, 87, 98, 210, 321, 432, 543, 654, 765, 876, 987, 3210, 4321, 5432, 6543, 7654, 8765, 9876, 43210, 54321, 65432, 76543, 87654, 98765, 543210, 654321, 765432, 876543, 987654

Offset

1,3

Comments

This finite sequence has 55 members. The last member is 9876543210. There are 11-k members with k digits. See A052016 for primes in this sequence. All members with 3 or more digits are straight-line numbers A135643.

Links

Table of n, a(n) for n=1..45.

Example

Last 10 members of this finite sequence:
a(45)=6543210
a(46)=7654321
a(47)=8765432
a(48)=9876543
a(49)=76543210
a(50)=87654321
a(51)=98765432
a(52)=876543210
a(53)=987654321
a(54)=9876543210

Mathematica

fQ[n_]:=Module[{id=IntegerDigits[n]}, n<10 || Union[Differences[id]]=={-1}]; Select[Range[0, 100000], fQ] (* Vladimir Joseph Stephan Orlovsky, Dec 29 2010 *)
Sort[Flatten[With[{t=Range[9, 0, -1]}, Table[FromDigits/@Partition[t, n, 1], {n, 10}]]]] (* Harvey P. Dale, Oct 31 2013 *)

Crossrefs

Cf. A052016, A135643, A138141.

Sequence in context: A158699 A247107 A061511 * A085890 A274842 A134817

Adjacent sequences: A138139 A138140 A138141 * A138143 A138144 A138145

Keyword

base,easy,fini,nonn

Author

Omar E. Pol, Mar 19 2008

Extensions

Examples corrected by Omar E. Pol, Dec 06 2008

Status

approved