A047899 a(1) = 7; for n > 0, a(n+1) = a(n) * sum of digits of a(n).

7, 49, 637, 10192, 132496, 3312400, 43061200, 688979200, 33759980800, 1755519001600, 70220760064000, 2387505842176000, 138475338846208000, 9693273719234560000, 736688802661826560000, 64828614634240737280000

Offset: 1

Author

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

Keywords

• nonn
• base
• easy

Links

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

Crossrefs

Cf. A047892 (start=2), A047912 (start=3), A047897 (start=5), A047898 (start=6), A047900 (start=8), A047901 (start=9), A047902 (start=11).

Programs

Haskell

a047899 n = a047899_list !! (n-1)
a047899_list = iterate a057147 7  -- Reinhard Zumkeller, Mar 19 2014

Formula

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