A350697 Smallest number m > 1 such that n * m = A350538(n) contains only even digits.

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

Offset

1,1

Comments

The smallest odd term is a(48) = 5 because 48*5 = 240.

Record values of a(n) are 2, 4, 32, 64, ...

Links

Table of n, a(n) for n=1..85.

Formula

a(n) = A350538(n) / n.

Example

The smallest proper multiple of 9 with only even digits is A350538(9) = 288, as 288 = 9 * 32, a(9) = 32.

Mathematica

a[n_] := Module[{k = 2*n}, While[! AllTrue[IntegerDigits[k], EvenQ], k += n]; k/n]; Array[a, 100] (* Amiram Eldar, Jan 12 2022 *)

Prog

(PARI) a(n) = my(k=2); while(#select(x->((x%2) == 1), digits(k*n)), k++); k; \\ Michel Marcus, Jan 12 2022

Crossrefs

Cf. A061807, A350536, A350537, A350538.

Sequence in context: A006643 A080217 A157901 * A327441 A335855 A297824

Adjacent sequences: A350694 A350695 A350696 * A350698 A350699 A350700

Keyword

nonn,base

Author

Bernard Schott, Jan 12 2022

Extensions

More terms from Michel Marcus, Jan 12 2022

Status

approved