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
KEYWORD
easy,nonn,base
AUTHOR
Miklos SZABO (mike(AT)ludens.elte.hu)
STATUS
approved