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A173944
Numbers n such that bigomega(lambda(n)) = lambda(bigomega(n)), where bigomega is the number of prime divisors of n (counted with multiplicity) and lambda is the Carmichael function.
1
1, 3, 4, 6, 16, 18, 20, 28, 30, 36, 40, 42, 44, 56, 60, 63, 66, 84, 88, 92, 126, 132, 138, 162, 184, 188, 236, 240, 270, 272, 276, 282, 304, 332, 354, 376, 408, 428, 450, 472, 496, 498, 500, 504, 564, 567, 592, 594, 642, 656
OFFSET
1,2
LINKS
FORMULA
EXAMPLE
236 is in the sequence because bigomega(lambda(236)) = bigomega(58) = 2 ,
lambda(bigomega(236)) = lambda(3) = 2.
MAPLE
with(numtheory): for n from 1 to 700 do:if bigomega(lambda(n))=lambda(bigomega(n))then
printf(`%d, `, n):else fi:od:
MATHEMATICA
aQ[n_] := PrimeOmega[CarmichaelLambda[n]] == CarmichaelLambda[PrimeOmega[n]]; Select[Range[700], aQ] (* Amiram Eldar, Aug 30 2019*)
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Nov 26 2010
STATUS
approved