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A350697
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Smallest number m > 1 such that n * m = A350538(n) contains only even digits.
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1
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2, 2, 2, 2, 4, 4, 4, 3, 32, 2, 2, 2, 2, 2, 4, 3, 4, 16, 12, 2, 2, 2, 2, 2, 8, 8, 18, 3, 14, 2, 2, 2, 2, 2, 8, 8, 6, 6, 12, 2, 2, 2, 2, 2, 64, 10, 6, 5, 14, 4, 4, 4, 8, 9, 4, 4, 4, 7, 14, 4, 4, 4, 14, 7, 4, 4, 4, 3, 12, 4, 4, 4, 28, 3, 8, 3, 6, 6, 34, 3, 6, 3, 8, 5, 8
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OFFSET
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1,1
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COMMENTS
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The smallest odd term is a(48) = 5 because 48*5 = 240.
Record values of a(n) are 2, 4, 32, 64, ...
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LINKS
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FORMULA
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EXAMPLE
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The smallest proper multiple of 9 with only even digits is A350538(9) = 288, as 288 = 9 * 32, a(9) = 32.
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MATHEMATICA
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a[n_] := Module[{k = 2*n}, While[! AllTrue[IntegerDigits[k], EvenQ], k += n]; k/n]; Array[a, 100] (* Amiram Eldar, Jan 12 2022 *)
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PROG
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(PARI) a(n) = my(k=2); while(#select(x->((x%2) == 1), digits(k*n)), k++); k; \\ Michel Marcus, Jan 12 2022
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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