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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A188641 Characteristic function of Niven (or Harshad) numbers. 6
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

a(A005349(n)) = 1; a(A065877(n)) = 0;

also a(A038186(n)) = 1.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for characteristic functions

Wikipedia, Harshad number

Eric Weisstein, Harshad Numbers

FORMULA

a(n) = A000007(A070635(n)).

PROG

(Haskell)

a188641 = (1 -) . signum . a070635

CROSSREFS

Cf. A007953, A188642.

Sequence in context: A105586 A202022 A136522 * A086299 A131364 A152066

Adjacent sequences:  A188638 A188639 A188640 * A188642 A188643 A188644

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Apr 07 2011

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 23 03:21 EDT 2019. Contains 328335 sequences. (Running on oeis4.)