Smallest number x such that sigma(x) = sigma(x(n)), where x(n) is the n-th arithmetic derivatives of x and x is not equal to x(n).

A246774

Smallest number x such that sigma(x) = sigma(x(n)), where x(n) is the n-th arithmetic derivatives of x and x is not equal to x(n).

Terms

    a(0) =60a(1) =482a(2) =3903a(3) =5667a(4) =175a(5) =68951a(6) =11039a(7) =76939a(8) =1157a(9) =22746a(10) =19847a(11) =16195a(12) =23806a(13) =345855a(14) =824059a(15) =269862a(16) =2484227a(17) =809358a(18) =94558183a(19) =98337630a(20) =6504935

External references