OFFSET
1,1
LINKS
Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000
EXAMPLE
30 = 2*3*5 belongs to this sequence, since its prime factors all have one digit and 30 is not a perfect power.
MATHEMATICA
lst1 = {}; lst2 = {}; r = 270; Do[b = IntegerDigits[FactorInteger[n]]; If[! PrimeQ[n] && Length[b[[-1, 1]]] == Length[b[[1, 1]]], AppendTo[lst1, n]], {n, 4, r}]; lst2 = Complement[lst1, Union[Flatten[Table[n^i, {i, 2, Log[2, r]}, {n, 2, r^(1/i)}]]]]; lst2
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Arkadiusz Wesolowski, Apr 23 2012
STATUS
approved