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A110086
Numbers k such that sigma(k) - phi(k) <= tau(k)^omega(k), where sigma = A000203, phi = A000010, tau = A000005 and omega = A001221.
7
1, 2, 3, 5, 6, 7, 10, 11, 12, 13, 15, 17, 18, 19, 20, 23, 24, 29, 30, 31, 36, 37, 41, 42, 43, 47, 53, 59, 60, 61, 66, 67, 70, 71, 73, 78, 79, 83, 84, 89, 90, 97, 101, 102, 103, 105, 107, 109, 110, 113, 114, 120, 126, 127, 130, 131, 132, 137, 138, 139, 140, 149, 150, 151
OFFSET
1,2
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
A051612(a(n)) <= A110088(a(n)).
MATHEMATICA
q[k_] := DivisorSigma[1, k] - EulerPhi[k] <= DivisorSigma[0, k]^PrimeNu[k]; Select[Range[160], q] (* Amiram Eldar, Sep 15 2024 *)
PROG
(PARI) is(n)=sigma(n)-eulerphi(n)<=numdiv(n)^omega(n) \\ Charles R Greathouse IV, Feb 14 2013
(Haskell)
a110086 n = a110086_list !! (n-1)
a110086_list = filter (\x -> a051612 x <= a110088 x) [1..]
-- Reinhard Zumkeller, Aug 05 2014
CROSSREFS
Union of A000040 and A110085.
Complement of A110086.
Sequence in context: A373376 A367861 A214432 * A107746 A024899 A114518
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 11 2005
STATUS
approved