A095992 - OEIS

A095992

a(1) = 30; for n > 1, a(n+1) = a(n) + {product of nonzero digits of a(n)}.

%I #12 Nov 21 2013 12:48:20

%S 30,33,42,50,55,80,88,152,162,174,202,206,218,234,258,338,410,414,430,

%T 442,474,586,826,922,958,1318,1342,1366,1474,1586,1826,1922,1958,2318,

%U 2366,2582,2742,2854,3174,3258,3498,4362,4506,4626,4914,5058,5258,5658

%N a(1) = 30; for n > 1, a(n+1) = a(n) + {product of nonzero digits of a(n)}.

%D From a puzzle; explanation found by Pierre Roger.

%H Frank Rubin, <a href="http://www.contestcen.com/series.htm">Number Series</a>

%t a[1] = 30; a[n_] := a[n] = Block[{s = Sort[ IntegerDigits[a[n - 1]]]}, While[ s[[1]] == 0, s = Drop[s, 1]]; a[n - 1] + Times @@ s]; Table[ a[n], {n, 50}]

%t nxt[n_] := n+Times@@Select[IntegerDigits[n], #>0&]; NestList[nxt,30,50] (* _Harvey P. Dale_, Jan 08 2011 *)

%Y Cf. A063108, A096347, A096972, A063108, A063425, A096922, A096923, A096924, A096925, A096926, A096927, A096928, A096929, A096930, A096931, A096973, A096987.

%K nonn,base,easy

%O 1,1

%A Julien Piquet (julipiquet(AT)yahoo.fr), Jul 18 2004

%E The proposer suggests that this web site may contain other sequences also.

%E Edited and extended by _Robert G. Wilson v_ and _Klaus Brockhaus_, Jul 20 2004