Numbers x such that (-1)sigma(x) | sigma(x), where (-1)sigma(x) is defined in A049060 and sigma(x) is the sum of the divisors of x (A000203).

A258077

Numbers x such that (-1)sigma(x) | sigma(x), where (-1)sigma(x) is defined in A049060 and sigma(x) is the sum of the divisors of x (A000203).

Terms

    a(0) =1a(1) =2a(2) =3a(3) =6a(4) =14a(5) =15a(6) =30a(7) =35a(8) =42a(9) =70a(10) =78a(11) =105a(12) =190a(13) =210a(14) =348a(15) =357a(16) =418a(17) =570a(18) =714a(19) =812a(20) =910a(21) =1045a(22) =1254a(23) =2090a(24) =2436a(25) =2730a(26) =3135a(27) =4060a(28) =4522a(29) =4674

External references