The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A047892 a(1) = 2; for n > 0, a(n+1) = a(n) * sum of digits of a(n). 15
 2, 4, 16, 112, 448, 7168, 157696, 5361664, 166211584, 5651193856, 276908498944, 19383594926080, 1298700860047360, 79220752462888960, 6733763959345561600, 592571228422409420800, 45035413360103115980800 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) mod 9 = A010712(n-1) for n > 1. - Reinhard Zumkeller, Sep 23 2007 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:=2; 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 NestList[# Total[IntegerDigits[#]]&, 2, 20] (* Harvey P. Dale, Jul 18 2011 *) PROG (Haskell) a047892 n = a047892_list !! (n-1) a047892_list = iterate a057147 2  -- Reinhard Zumkeller, Mar 19 2014 CROSSREFS Cf. A004207. Cf. A007953. Cf. A047912 (start=3), A047897 (start=5), A047898 (start=6), A047899 (start=7), A047900 (start=8), A047901 (start=9), A047902 (start=11). Sequence in context: A135249 A318154 A110365 * A275911 A334351 A009200 Adjacent sequences:  A047889 A047890 A047891 * A047893 A047894 A047895 KEYWORD nonn,base,easy,nice AUTHOR Miklos SZABO (mike(AT)ludens.elte.hu) EXTENSIONS Offset changed by Reinhard Zumkeller, Mar 19 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 22 21:29 EDT 2021. Contains 345393 sequences. (Running on oeis4.)