OFFSET
1,2
COMMENTS
For smallest prime divisors see A138960.
LINKS
Robert Price, Table of n, a(n) for n = 1..60
MATHEMATICA
a = {}; b = {}; Do[w = RealDigits[n]; w = First[w]; Do[AppendTo[a, w[[Length[w] - k + 1]]], {k, 1, Length[w]}]; p = FromDigits[a]; AppendTo[b, First[Last[FactorInteger[p]]]], {n, 1, 18}]; b
A137957[n_] := FromDigits[Flatten[Reverse /@ IntegerDigits[Range[n]]]];
Table[First[Last[FactorInteger[A137957[n]]]], {n, 39}] (* Robert Price, May 10 2019 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Artur Jasinski, Apr 04 2008
STATUS
approved