Number of values of k for which sigma(k)-k is a permutation of decimal digits of k, for k < 2^n.
A216393
Number of values of k for which sigma(k)-k is a permutation of decimal digits of k, for k < 2^n.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =1a(4) =2a(5) =2a(6) =2a(7) =2a(8) =4a(9) =5a(10) =6a(11) =8a(12) =13a(13) =17a(14) =32a(15) =47a(16) =63a(17) =98a(18) =189a(19) =279a(20) =437a(21) =782a(22) =1368a(23) =2062a(24) =3611a(25) =6311a(26) =9674
External references
- oeis: A216393