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A246757 Largest n-digit number divisible by the product of its decimal digits. 1
9, 36, 816, 9612, 93744, 973728, 9939915, 99221112, 997711344, 9993393711, 99934212672, 999641938176, 9999121936392, 99996414731136, 999994123418112, 9999982411646976, 99999318116613312, 999991631331122112, 9999944111773994112, 99999911232931433472, 999999832211912282112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The smallest such numbers are given by repunits A000042 or A002275.

LINKS

Max Alekseyev, Table of n, a(n) for n = 1..30

PROG

(PARI) { A246757(n) = my(m, d, p, q); m=n\2; forstep(k=10^m-1, (10^m-1)/9, -1, d=digits(k); q=prod(i=1, #d, d[i]); if(q==0, next); forstep(s=(((k+1)*10^(n-m))\q)*q, k*10^(n-m), -q,  d=digits(s); p=prod(i=1, #d, d[i]); if(p==0 || s%p, next); return(s) )) }

(Python)

from operator import mul

from functools import reduce

def A246757(n):

    for i in range(10**n-1, int('1'*n)-1, -1):

        pd = reduce(mul, (int(d) for d in str(i)))

        if pd and not i % pd:

            return i # Chai Wah Wu, Sep 08 2014

CROSSREFS

Subsequence of A007602.

Sequence in context: A223306 A272890 A129425 * A079655 A203764 A053949

Adjacent sequences:  A246754 A246755 A246756 * A246758 A246759 A246760

KEYWORD

nonn,base

AUTHOR

Max Alekseyev, Sep 02 2014

STATUS

approved

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Last modified May 25 22:51 EDT 2022. Contains 354073 sequences. (Running on oeis4.)