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A237275 Smallest k divisible by the n-th power of its last decimal digit > 1. 0
2, 2, 12, 32, 32, 32, 192, 512, 512, 512, 3072, 8192, 8192, 8192, 49152, 131072, 131072, 131072, 786432, 2097152, 2097152, 2097152, 12582912, 33554432, 33554432, 33554432 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Conjecture: a(n) == 2 (mod 10).

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n) = 3*2^n if n mod 4 = 2; 2^(n+2-((n+1) mod 4)) otherwise. - Jon E. Schoenfield, Sep 12 2017

EXAMPLE

a(0) = 2 because 2 is divisible by 2^0 = 1.

a(1) = 2 because 2 is divisible by 2^1 = 2.

a(2) = 12 because 12 is divisible by 2^2 = 4.

MATHEMATICA

Do[k=1; While[!Total[Transpose[IntegerDigits[k][[-1]]>0&&Mod[k, IntegerDigits[k][[-1]]^n]==0&&!Mod[k, 10]==1], k++]]; Print[n, " ", k-1], {n, 0, 25}]

CROSSREFS

Cf. A132359.

Sequence in context: A033886 A185144 A185344 * A087131 A199240 A173842

Adjacent sequences:  A237272 A237273 A237274 * A237276 A237277 A237278

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Apr 22 2014

STATUS

approved

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Last modified September 29 12:15 EDT 2020. Contains 337431 sequences. (Running on oeis4.)