A100799 - OEIS

%I #6 Jun 10 2023 13:11:54

%S 1,2,2,4,8,32,48,192,576,3780,35280,40320,5760,5040,4200,160,48,192,

%T 576,3780,35280,40320,5760,5040,4200,160,48,192,576,3780,35280,40320,

%U 5760,5040,4200,160,48,192,576,3780,35280,40320,5760,5040,4200,160,48

%N a(1) = 1, a(2) = 2, a(n) = product of nonzero digits of previous two terms.

%C Pattern of ten terms repeats beginning with a(7)=48.

%t nxt[{a_,b_}]:={b,Times@@Select[Flatten[IntegerDigits/@{a,b}],#>0&]}; NestList[nxt,{1,2},50][[;;,1]] (* or *) PadRight[{1,2,2,4,8,32},50,{35280,40320,5760,5040,4200,160,48,192,576,3780}] (* _Harvey P. Dale_, Jun 10 2023 *)

%K base,easy,nonn

%O 1,2

%A _Amarnath Murthy_, Dec 17 2004

%E Corrected and extended by _Ray Chandler_, Dec 19 2004