Numbers of the form ab such that phi(ab) = a*b - 1 where ab is the concatenation of a and b.

A336192

Numbers of the form ab such that phi(ab) = a*b - 1 where ab is the concatenation of a and b.

Terms

    a(0) =1385a(1) =1397a(2) =15663a(3) =19835a(4) =37037a(5) =238903a(6) =719719a(7) =1983035a(8) =4337785a(9) =5946445a(10) =8099989a(11) =15276063a(12) =64438507a(13) =97919791a(14) =238639687a(15) =325776657a(16) =1926629941a(17) =3228792383a(18) =4387457627a(19) =4652069941a(20) =9801019901a(21) =44898935609a(22) =68135795923a(23) =115563539473a(24) =129898064149a(25) =390084197561

External references