Sigma unitary-sigma perfect numbers: numbers m which satisfy the following equation for some integer k: sigma(usigma(m)) = k*m where usigma(m) is sum of unitary divisors of m.

A083288

Sigma unitary-sigma perfect numbers: numbers m which satisfy the following equation for some integer k: sigma(usigma(m)) = k*m where usigma(m) is sum of unitary divisors of m.

Terms

    a(0) =1a(1) =2a(2) =9a(3) =15a(4) =18a(5) =21a(6) =40a(7) =42a(8) =60a(9) =104a(10) =120a(11) =288a(12) =312a(13) =756a(14) =1023a(15) =1170a(16) =2160a(17) =2520a(18) =3024a(19) =4092a(20) =6048a(21) =6552a(22) =8184a(23) =17850a(24) =18720a(25) =29127a(26) =30690a(27) =40768a(28) =58254a(29) =79794

External references