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

1,1

Links

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

Formula

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

Prog

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

Crossrefs

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

Sequence in context: A125796 A135745 A080895 * A229041 A263247 A259990

Adjacent sequences: A047896 A047897 A047898 * A047900 A047901 A047902

Keyword

nonn,base,easy

Author

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

Status

approved