A188641 Characteristic function of Niven (or Harshad) numbers.

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

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

Eric Weisstein, Harshad Numbers

Wikipedia, Harshad number

Index entries for characteristic functions

Formula

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

Prog

(Haskell)
a188641 = (1 -) . signum . a070635

Crossrefs

Cf. A007953, A188642.

Sequence in context: A202022 A136522 A352871 * A086299 A131364 A152066

Adjacent sequences: A188638 A188639 A188640 * A188642 A188643 A188644

Keyword

nonn,base

Author

Reinhard Zumkeller, Apr 07 2011

Status

approved