OFFSET
1,1
COMMENTS
Numbers k such that the number of prime divisors (counted with multiplicity) of k is equal to the number of prime divisors (counted with multiplicity) of the arithmetic derivative of k.
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
PROG
(PARI) arde(n) = sum(i=1, #f=factor(n)~, n/f[1, i]*f[2, i])
select(k->bigomega(k)==bigomega(arde(k)), vector(400, k, k+1))
CROSSREFS
KEYWORD
nonn
AUTHOR
Colin Barker, Jan 27 2017
STATUS
approved