Numbers m such that uphi(sigma(m)) = 2m, where the unitary phi function (A047994) is defined by: if x = p1^r1*p2^r2*p3^r3*... then uphi(x) = (p1^r1 - 1)*(p2^r2 - 1)*(p3^r3 - 1)*...
A030165
Numbers m such that uphi(sigma(m)) = 2m, where the unitary phi function (A047994) is defined by: if x = p1^r1*p2^r2*p3^r3*... then uphi(x) = (p1^r1 - 1)*(p2^r2 - 1)*(p3^r3 - 1)*...
Terms
- a(0) =36a(1) =252a(2) =288a(3) =756a(4) =1116a(5) =1512a(6) =2016a(7) =4572a(8) =6048a(9) =8928a(10) =24192a(11) =36576a(12) =62208a(13) =115200a(14) =136080a(15) =294876a(16) =806400a(17) =2359008a(18) =2419200a(19) =3571200a(20) =4147200a(21) =4718556a(22) =6193152a(23) =10782720a(24) =14630400a(25) =18874332a(26) =20575296a(27) =29030400a(28) =30108672a(29) =37748448
External references
- oeis: A030165