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A047898 a(1) = 6; for n > 0, a(n+1) = a(n) * (sum of digits of a(n)). 9

%I

%S 6,36,324,2916,52488,1417176,38263752,1377495072,61987278240,

%T 3347313024960,150629086123200,6778308875544000,488038239039168000,

%U 35138753210820096000,2213741452281666048000,159389384564279955456000

%N a(1) = 6; for n > 0, a(n+1) = a(n) * (sum of digits of a(n)).

%H Reinhard Zumkeller, <a href="/A047898/b047898.txt">Table of n, a(n) for n = 1..250</a>

%F a(n+1) = A057147(a(n)). - _Reinhard Zumkeller_, Mar 19 2014

%p P:=proc(n) local a,i,k,w; a:=6; print(a); for i from 1 by 1 to n do w:=0;k:=a; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; a:=a*w; print(a); od; end: P(1000); # _Paolo P. Lava_, Apr 27 2007

%t Nest[Append[#, # Total@ IntegerDigits@ # &@ Last[#]] &, {6}, 15] (* _Michael De Vlieger_, Jul 08 2019 *)

%o (Haskell)

%o a047898 n = a047898_list !! (n-1)

%o a047898_list = iterate a057147 6 -- _Reinhard Zumkeller_, Mar 19 2014

%o (Python)

%o A047898_list, l = [6], 6

%o for _ in range(10**2):

%o ....l *= sum(int(d) for d in str(l))

%o ....A047898_list.append(l) # _Chai Wah Wu_, Jan 04 2015

%Y Cf. A047892 (start=2), A047912 (start=3), A047897 (start=5), A047899 (start=7), A047900 (start=8), A047901 (start=9), A047902 (start=11).

%K easy,nonn,base

%O 1,1

%A Miklos SZABO (mike(AT)ludens.elte.hu)

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Last modified July 23 12:19 EDT 2021. Contains 346259 sequences. (Running on oeis4.)