A360073 a(n) is the greatest divisor of n divisible by the product of its own digits.
1, 2, 3, 4, 5, 6, 7, 8, 9, 5, 11, 12, 1, 7, 15, 8, 1, 9, 1, 5, 7, 11, 1, 24, 5, 2, 9, 7, 1, 15, 1, 8, 11, 2, 7, 36, 1, 2, 3, 8, 1, 7, 1, 11, 15, 2, 1, 24, 7, 5, 3, 4, 1, 9, 11, 8, 3, 2, 1, 15, 1, 2, 9, 8, 5, 11, 1, 4, 3, 7, 1, 36, 1, 2, 15, 4, 11, 6, 1, 8, 9
Offset: 1
Examples
For n = 10: - the divisors of 10 are 1, 2, 5 and 10, - 5 is divisible by 5 whereas 10 is not divisible by 1*0, - so a(10) = 5.
Links
Programs
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PARI
a(n) = { fordiv (n, d, my (t=n/d, p=vecprod(digits(t))); if (p && t%p==0, return (t))) }
Formula
a(n) = n iff n belongs to A007602.
Comments