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A006919 Write down all the prime divisors in previous term.
(Formerly M4581)
3
8, 222, 2337, 31941, 33371313, 311123771, 7149317941, 22931219729, 112084656339, 3347911118189, 11613496501723, 97130517917327, 531832651281459, 3331113965338635107, 3331113965338635107 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

H. Jaleebi, personal communication.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=1..15.

P. De Geest, Home Primes

MATHEMATICA

g[ n_ ] := (x = n; d = {}; While[ FactorInteger[ x ] != {}, f = FactorInteger[ x, FactorComplete -> True ][ [ 1, 1 ] ]; x = x/f; AppendTo[ d, IntegerDigits[ f ] ] ]; FromDigits[ Flatten[ d ] ]); NestList[ g, 8, 15 ]

NestList[FromDigits[Flatten[IntegerDigits/@(Table[First[#], {Last[#]}]& /@ FactorInteger[#])]]&, 8, 15] (* Harvey P. Dale, Dec 04 2011 *)

CROSSREFS

Cf. A056938, A037271-A037276, A048985, A048986, A049065.

Sequence in context: A183261 A316954 A299734 * A179122 A300349 A300434

Adjacent sequences:  A006916 A006917 A006918 * A006920 A006921 A006922

KEYWORD

nonn,base,nice

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Robert G. Wilson v, Sep 05 2000, who remarks that sequence stabilizes at 13th term with a prime.

STATUS

approved

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Last modified October 20 12:34 EDT 2018. Contains 316379 sequences. (Running on oeis4.)