Composite x such that [(x-1)' + (x+1)'] / x' is an integer, where x' is the arithmetic derivative of x.

A246769

Composite x such that [(x-1)' + (x+1)'] / x' is an integer, where x' is the arithmetic derivative of x.

Terms

    a(0) =10a(1) =14a(2) =1234a(3) =9302a(4) =15621a(5) =45069a(6) =275825a(7) =1496771a(8) =3901747a(9) =3965572a(10) =4800842a(11) =12089923a(12) =13725353a(13) =60247178a(14) =86123531a(15) =141164047a(16) =400351433a(17) =577144967a(18) =733863869a(19) =797811821a(20) =1107698663a(21) =1230427279a(22) =1745874461a(23) =1963869823a(24) =2069222929a(25) =2568664561a(26) =3288702721

External references