login
This site is supported by donations to The OEIS Foundation.

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A037124 Numbers that contain only one nonzero digit. 17
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Starting with 1: next greater number not containing the highest digit (see also A098395). - Reinhard Zumkeller, Oct 31 2004

a(n) = A140740(n+9, 9). - Reinhard Zumkeller, May 26 2008

A055640(a(n)) = 1. - Reinhard Zumkeller, May 03 2011

A193459(a(n)) = A000005(a(n)), subsequence of A193460.

Sum_{n>0} 1/a(n)^s = (10^s)*(Zeta(s) - Zeta(s,10))/(10^s-1), with (s>1). - Enrique Pérez Herrero, Feb 05 2013

REFERENCES

Maltenfort, Michael. "Characterizing Additive Systems." The American Mathematical Monthly 124.2 (2017): 132-148.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Index entries for 10-automatic sequences.

FORMULA

a(n) = ((n mod 9) + 1) * 10^floor(n/9). E.g., a(39) = ((39 mod 9) + 1) * 10^floor(39/9) = (3 + 1) * 10^4 = 40000. - Carl R. White, Jan 08 2004

a(n) = A051885(n-1) + 1. - Reinhard Zumkeller, Jan 03 2008, Jul 10 2011

A138707(a(n)) = A000005(a(n)); A061116 is a subsequence. - Reinhard Zumkeller, Mar 26 2008

a(n+1) = a(n) + a(n - n mod 9). - Reinhard Zumkeller, May 26 2008

a(n) = (10^floor((n - 1)/9))*(n - 9*floor((n - 1)/9)). - José de Jesús Camacho Medina, Nov 10 2014

From Chai Wah Wu, May 28 2016: (Start)

a(n) = 10*a(n-9).

G.f.: x*(9*x^8 + 8*x^7 + 7*x^6 + 6*x^5 + 5*x^4 + 4*x^3 + 3*x^2 + 2*x + 1)/(1 - 10*x^9). (End)

MATHEMATICA

Table[(10^Floor[(n - 1)/9])*(n - 9*Floor[(n - 1)/9]), {n, 1, 50}](* José de Jesús Camacho Medina, Nov 10 2014 *)

PROG

(Haskell)

a037124 n = a037124_list !! (n-1)

a037124_list = f [1..9] where f (x:xs) = x : f (xs ++ [10*x])

-- Reinhard Zumkeller, May 03 2011

(MAGMA) [((n mod 9)+1) * 10^Floor(n/9): n in [0..50]]; // Vincenzo Librandi, Nov 11 2014

(PARI) is(n)=n>1 && n/10^valuation(n, 10)<10 \\ Charles R Greathouse IV, Jan 29 2017

CROSSREFS

Cf. A000079, A038754, A133464, A140730.

Sequence in context: A051596 A071061 * A273737 A201982 A166508 A223080

Adjacent sequences:  A037121 A037122 A037123 * A037125 A037126 A037127

KEYWORD

nonn,base,easy

AUTHOR

Vasiliy Danilov (danilovv(AT)usa.net), Jun 15 1998

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 30 03:27 EDT 2017. Contains 287305 sequences.