A225296 Numbers divisible by their first digit cubed (excluding those whose first digit is 1).

24, 200, 208, 216, 224, 232, 240, 248, 256, 264, 272, 280, 288, 296, 324, 351, 378, 448, 500, 648, 2000, 2008, 2016, 2024, 2032, 2040, 2048, 2056, 2064, 2072, 2080, 2088, 2096, 2104, 2112, 2120, 2128, 2136, 2144, 2152, 2160, 2168, 2176, 2184, 2192, 2200, 2208

Offset: 1

Author

Kevin L. Schwartz and Christian N. K. Anderson, May 04 2013

Keywords

• nonn
• base

Comments

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

Examples

			448 is divisible by 4^3.
		

Links

• Christian N. K. Anderson, Table of n, a(n) for n = 1..10000
• Christian N. K. Anderson, Ulam Spiral of first 10000 terms.

Crossrefs

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

Programs

Mathematica

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

R

x=0; y=rep(0,1000); len=0
firstdig<-function(x) as.numeric(substr(as.character(x),1,1))
isint<-function(x) x==as.integer(x)
while(len<1000) if((fd=firstdig((x=x+1)))>1) if(isint(x/fd^3)) y[(len=len+1)]=x