Number of values of k for which phi(k) is a permutation of decimal digits of k, for k < 2^n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =3a(6) =3a(7) =3a(8) =5a(9) =5a(10) =5a(11) =8a(12) =19a(13) =21a(14) =34a(15) =55a(16) =81a(17) =130a(18) =221a(19) =407a(20) =515a(21) =850a(22) =1787a(23) =2287a(24) =3968a(25) =8176a(26) =12332a(27) =18560a(28) =36832a(29) =71375