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A263111
Ordinal transform of the arithmetic derivative A003415.
2
1, 2, 1, 2, 1, 3, 1, 4, 1, 1, 1, 5, 1, 6, 1, 1, 1, 7, 1, 8, 1, 1, 1, 9, 1, 2, 1, 1, 2, 10, 1, 11, 1, 1, 1, 2, 1, 12, 2, 2, 1, 13, 1, 14, 1, 1, 1, 15, 1, 2, 1, 1, 1, 16, 1, 3, 1, 1, 2, 17, 2, 18, 1, 1, 1, 1, 1, 19, 1, 1, 1, 20, 1, 21, 2, 1, 2, 2, 1, 22, 1, 1
OFFSET
0,2
COMMENTS
n is the a(n)-th nonnegative integer having its arithmetic derivative.
LINKS
FORMULA
a(n) = |{ j in {0..n} : A003415(j) = A003415(n) }|.
MAPLE
p:= proc() 0 end:
a:= proc(n) option remember; local t;
t:= n*add(i[2]/i[1], i=ifactors(n)[2]);
p(t):= p(t)+1
end:
seq(a(n), n=0..100);
CROSSREFS
Cf. A003415.
Sequence in context: A243546 A243554 A361734 * A260438 A112197 A112198
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 09 2015
STATUS
approved