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!)
A087143 Numbers n such that sum of digits of n is divisible by digital root of n. 2
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 48, 50, 51, 52, 53, 54, 55, 57, 60, 61, 62, 63, 64, 66, 70, 71, 72, 73, 75, 80, 81, 82, 84, 90 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A007953(a(n)) mod A010888(a(n)) = 0; multiples of 9 are a subsequence (A008591, n>0).

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

EXAMPLE

84 is a term because 12 (its sum of digits) is divisible by 3 (its digital root).

MAPLE

A087143 := proc(n) option remember: local k: if(n=1)then return 1:fi: for k from procname(n-1)+1 do if(add(d, d=convert(k, base, 10)) mod (((k-1) mod 9) + 1) = 0)then return k: fi: od: end: seq(A087143(n), n=1..100); # Nathaniel Johnston, May 05 2011

MATHEMATICA

sddrQ[n_]:=Module[{sd=Total[IntegerDigits[n]], dr}, dr=sd; While[dr>9, dr= Total[ IntegerDigits[dr]]]; Divisible[sd, dr]]; Select[Range[100], sddrQ] (* Harvey P. Dale, May 22 2013 *)

CROSSREFS

Cf. A010888, A064807. Complement of A087144.

Sequence in context: A273887 A194906 A160546 * A080683 A174228 A197640

Adjacent sequences:  A087140 A087141 A087142 * A087144 A087145 A087146

KEYWORD

nonn,easy,base

AUTHOR

Reinhard Zumkeller, Aug 18 2003

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 March 4 23:52 EST 2021. Contains 341812 sequences. (Running on oeis4.)