

A267795


Integers n such that n, 2n, 3n ... 10n contain almost equally many copies of each base 10 digit.


1



1, 9, 109, 909, 10909, 90909, 1090909, 9090909, 13431958, 25834963, 32973507, 38296415, 45096237, 51546969, 94845303, 96237045, 109090909, 113431958, 126084879, 132868745, 132875488, 133595248, 134319558, 134755956, 134758658, 137584878, 143865844, 153584878
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OFFSET

1,2


COMMENTS

Here 'almost equally many' means that the most common digit appears only once more than the least common.


LINKS

Lars Blomberg, Table of n, a(n) for n = 1..4000


EXAMPLE

The first 10 multiples of 109 are 109, 218, 327, 436, 545, 654, 763, 872, 981, 1090. Every digit appears 3 times except for '1' which appears 4 times. It is clear that all numbers of the form 10909..0909 and 90909..0909 appear in the list, and it seems likely that these are the only members.


PROG

(Python)
def f(n):
""" This returns True iff n is in the sequence """
l = [ n * i for i in range(1, 11) ]
s = "".join(str(i) for i in l)
c = [ s.count(str(j)) for j in range(10) ]
return min(c) >= max(c)  1


CROSSREFS

Cf. A038365.
Sequence in context: A157906 A166846 A058421 * A128876 A199030 A288692
Adjacent sequences: A267792 A267793 A267794 * A267796 A267797 A267798


KEYWORD

nonn,easy,base


AUTHOR

Jack W Grahl, Jan 20 2016


EXTENSIONS

a(7)a(28) from Lars Blomberg, Aug 11 2016


STATUS

approved



