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A281686
Numbers k such that A001222(k) = A001222(A003415(k)).
2
4, 8, 9, 14, 21, 25, 26, 27, 32, 33, 36, 38, 46, 48, 49, 50, 54, 57, 62, 69, 74, 80, 85, 88, 93, 94, 99, 100, 106, 121, 125, 128, 129, 133, 134, 145, 156, 166, 169, 176, 177, 178, 205, 207, 213, 216, 217, 218, 226, 230, 237, 240, 242, 243, 248, 249, 252, 253
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
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