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

6, 36, 324, 2916, 52488, 1417176, 38263752, 1377495072, 61987278240, 3347313024960, 150629086123200, 6778308875544000, 488038239039168000, 35138753210820096000, 2213741452281666048000, 159389384564279955456000

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

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