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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A101170 a(n) divides the number formed by concatenating the sum of the digits of a(n) with a(n). 1
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 48, 50, 60, 70, 75, 80, 90, 100, 120, 125, 150, 180, 200, 225, 240, 250, 300, 360, 375, 400, 450, 480, 500, 600, 700, 750, 800, 900, 1000, 1125, 1200, 1250, 1500, 1800, 1875, 2000, 2250, 2400, 2500 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The most common factor is 11, which catches most of the trivial cases such as 5000 (which when concatenated with its digit sum yields 55000... 11 * 5000). See A101171 for the first sequence member which uses a new factor.

There are only a finite number of terms ending with a nonzero digit. See A101171 for the proof. [From Max Alekseyev, May 08 2009]

LINKS

Table of n, a(n) for n=1..59.

EXAMPLE

a(50)=1125 because the number formed by concatenating the digit sum of 1125 (9) with 1125 yields a number (91125) that 1125 evenly divides. 91125 / 1125 = 81.

CROSSREFS

Cf. A101171.

Sequence in context: A036965 A133184 A102576 * A236686 A246084 A260768

Adjacent sequences:  A101167 A101168 A101169 * A101171 A101172 A101173

KEYWORD

base,nonn

AUTHOR

Chuck Seggelin (seqfan(AT)plastereddragon.com), Dec 03 2004

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 October 1 03:36 EDT 2020. Contains 337441 sequences. (Running on oeis4.)