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A189036
a(n)= lcm(n,n')/gcd(n,n'), where n' is the arithmetic derivative of n.
2
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
OFFSET
1,2
COMMENTS
Least common multiple of n and its arithmetic derivative divided by greatest common divisor of n and its arithmetic derivative.
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
KEYWORD
nonn
AUTHOR
Giorgio Balzarotti, Apr 15 2011
STATUS
approved