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A138963 a(1)=1; a(n+1) = the largest prime divisor of A138793(n+1). 1
1, 7, 107, 149, 953, 218107, 402859, 4877, 379721, 4349353, 169373, 182473, 1940144339383, 2184641, 437064932281, 5136696159619, 67580875919190833, 1156764458711, 464994193118899, 4617931439293 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For the smallest prime divisors of A138793 see A138962.

LINKS

Robert Price, Table of n, a(n) for n = 1..45

MATHEMATICA

b = {}; a = {}; Do[w = RealDigits[n]; w = First[w]; Do[AppendTo[a, w[[k]]], {k, 1, Length[w]}]; p = FromDigits[Reverse[a]]; AppendTo[b, First[Last[FactorInteger[p]]]], {n, 1, 31}]; b (* Artur Jasinski, Apr 04 2008 *)

lst = {}; Table[First[Last[FactorInteger[FromDigits[Reverse[lst = Join[lst, IntegerDigits[n]]]]]]], {n, 1, 10}] (* Robert Price, Mar 22 2015 *)

CROSSREFS

Cf. A104759, A000422, A116504, A007908, A116505, A104759, A075019, A075020, A075021, A075022, A138789, A138790, A138958, A138959, A138960, A138962.

Sequence in context: A231899 A188407 A075021 * A141932 A002687 A166547

Adjacent sequences:  A138960 A138961 A138962 * A138964 A138965 A138966

KEYWORD

nonn,base

AUTHOR

Artur Jasinski, Apr 04 2008

STATUS

approved

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Last modified June 15 20:50 EDT 2019. Contains 324145 sequences. (Running on oeis4.)