A189036 - OEIS

A189036

a(n)= lcm(n,n')/gcd(n,n'), where n' is the arithmetic derivative of n.

0, 2, 3, 1, 5, 30, 7, 6, 6, 70, 11, 12, 13, 126, 120, 2, 17, 42, 19, 30, 210, 286, 23, 66, 10, 390, 1, 56, 29, 930, 31, 10, 462, 646, 420, 15, 37, 798, 624, 170, 41, 1722, 43, 132, 195, 1150, 47, 21, 14, 90, 1020, 182, 53, 6, 880, 322, 1254, 1798, 59, 345, 61, 2046, 357, 3, 1170, 4026, 67, 306, 1794, 4130, 71, 78, 73, 2886, 165, 380, 1386, 5538, 79, 55, 12, 3526, 83, 651, 1870, 3870, 2784, 770, 89, 1230, 1820, 552, 3162, 4606, 2280, 102, 97, 154, 825, 35

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OFFSET

1,2

COMMENTS

Least common multiple of n and its arithmetic derivative divided by greatest common divisor of n and its arithmetic derivative.

LINKS

Table of n, a(n) for n=1..100.

FORMULA

a(n) = lcm(n,n')/gcd(n,n') = A086130(n)/A085731(n).

EXAMPLE

n = 8, n'= 12, lcm(8,12)= 24, gcd(8,12)= 4, hence a(8)=24/4 = 6.

CROSSREFS