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!)
A110400 a(1) = 1, a(2) = 21; for n>2, a(n) is the least number whose neighboring digit difference forms a(n-1) such that a(n+1) also exists. 0
1, 21, 132, 1031, 10032, 100031, 1000032, 10000031, 100000032, 1000000031, 10000000032, 100000000031, 1000000000032, 10000000000031, 100000000000032, 1000000000000031, 10000000000000032, 100000000000000031 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(2) = 21 (chosen) and not 10 so that the sequence extends nontrivially.

A040115(a(n+1)) = a(n). - David Wasserman, Oct 02 2005

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

After 8421 two possible candidates are 91532 and 91576 but there is no number with digit difference 91576 hence the next term is 91532.

1031 is followed by 10032 because the absolute differences between the numbers 1, 0, 0, 3, 2 are 1, 0, 3, 1.

CROSSREFS

Cf. A011557.

Sequence in context: A228283 A157624 A008384 * A308348 A089369 A328861

Adjacent sequences:  A110397 A110398 A110399 * A110401 A110402 A110403

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Jul 29 2005

EXTENSIONS

Corrected and extended by David Wasserman, Oct 02 2005

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 16:23 EST 2021. Contains 349423 sequences. (Running on oeis4.)