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Numbers divisible by their first digit cubed (excluding those whose first digit is 1).
3

%I #22 Jan 13 2019 19:39:06

%S 24,200,208,216,224,232,240,248,256,264,272,280,288,296,324,351,378,

%T 448,500,648,2000,2008,2016,2024,2032,2040,2048,2056,2064,2072,2080,

%U 2088,2096,2104,2112,2120,2128,2136,2144,2152,2160,2168,2176,2184,2192,2200,2208

%N Numbers divisible by their first digit cubed (excluding those whose first digit is 1).

%C Numbers where floor(n/10^floor(log(n)))^3 | n.

%H Christian N. K. Anderson, <a href="/A225296/b225296.txt">Table of n, a(n) for n = 1..10000</a>

%H Christian N. K. Anderson, <a href="/A225296/a225296_1.gif">Ulam Spiral</a> of first 10000 terms.

%e 448 is divisible by 4^3.

%t dfdcQ[n_]:=Module[{fidn=IntegerDigits[n][[1]]},fidn!=1&&Divisible[ n,fidn^3]]; Select[Range[2500],dfdcQ] (* _Harvey P. Dale_, Jan 13 2019 *)

%o (R) x=0; y=rep(0,1000); len=0

%o firstdig<-function(x) as.numeric(substr(as.character(x),1,1))

%o isint<-function(x) x==as.integer(x)

%o while(len<1000) if((fd=firstdig((x=x+1)))>1) if(isint(x/fd^3)) y[(len=len+1)]=x

%Y Cf. A132359, A034709, A034837, A005349, A007602, A034838.

%K nonn,base

%O 1,1

%A _Kevin L. Schwartz_ and _Christian N. K. Anderson_, May 04 2013