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, 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

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

A001222(A002322(n))=A002322(A001222(n)).

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

Cf. A001222 A002322.

Sequence in context: A122727 A347056 A089249 * A092933 A122849 A068573

Adjacent sequences: A173941 A173942 A173943 * A173945 A173946 A173947

Keyword

nonn

Author

Michel Lagneau, Nov 26 2010

Status

approved