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A047898 a(1) = 6; for n > 0, a(n+1) = a(n) * (sum of digits of a(n)). 9
6, 36, 324, 2916, 52488, 1417176, 38263752, 1377495072, 61987278240, 3347313024960, 150629086123200, 6778308875544000, 488038239039168000, 35138753210820096000, 2213741452281666048000, 159389384564279955456000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..250

FORMULA

a(n+1) = A057147(a(n)). - Reinhard Zumkeller, Mar 19 2014

MAPLE

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

MATHEMATICA

Nest[Append[#, # Total@ IntegerDigits@ # &@ Last[#]] &, {6}, 15] (* Michael De Vlieger, Jul 08 2019 *)

PROG

(Haskell)

a047898 n = a047898_list !! (n-1)

a047898_list = iterate a057147 6  -- Reinhard Zumkeller, Mar 19 2014

(Python)

A047898_list, l = [6], 6

for _ in range(10**2):

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

....A047898_list.append(l) # Chai Wah Wu, Jan 04 2015

CROSSREFS

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

Sequence in context: A125795 A138418 A064239 * A337042 A098559 A129584

Adjacent sequences:  A047895 A047896 A047897 * A047899 A047900 A047901

KEYWORD

easy,nonn,base

AUTHOR

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

STATUS

approved

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Last modified June 16 18:25 EDT 2021. Contains 345066 sequences. (Running on oeis4.)