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A029455 Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 10 (most significant digit on left). 6
1, 2, 3, 5, 6, 9, 10, 12, 15, 18, 20, 25, 27, 30, 36, 45, 50, 54, 60, 69, 75, 90, 100, 108, 120, 125, 135, 150, 162, 180, 200, 216, 225, 248, 250, 270, 300, 324, 360, 375, 405, 450, 470, 500, 540, 558, 600, 648, 675, 710, 750, 810, 900, 1000, 1053, 1080, 1116 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Numbers n such that n divides A007908(n).

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..637, n = 1..236 from M. F. Hasler.

EXAMPLE

n = 13 is not a term since 12345678910111213 is not divisible by 13.

PROG

(PARI) c=0; for(d=1, 1e9, for(n=d, -1+d*=10, (c=c*d+n)%n || print1(n", ")); d--) \\ M. F. Hasler, Sep 11 2011

(Python)

A029455_list, r = [], 0

for n in range(1, 10**6+1):

....r = r*10**len(str(n))+n

....if not (r % n):

........A029455_list.append(n) # Chai Wah Wu, Nov 05 2014

CROSSREFS

Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.

See A171785 for numbers that divide the concatenation of a(1) through a(n).

Sequence in context: A047331 A288480 A029451 * A234718 A294849 A320226

Adjacent sequences:  A029452 A029453 A029454 * A029456 A029457 A029458

KEYWORD

nonn,base

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified March 19 11:29 EDT 2019. Contains 321329 sequences. (Running on oeis4.)