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

1,1

Comments

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

Links

Christian N. K. Anderson, Table of n, a(n) for n = 1..10000

Christian N. K. Anderson, Ulam Spiral of first 10000 terms.

Example

448 is divisible by 4^3.

Mathematica

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

Prog

(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

Crossrefs

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

Sequence in context: A126519 A260358 A198396 * A048355 A132458 A055857

Adjacent sequences: A225293 A225294 A225295 * A225297 A225298 A225299

Keyword

nonn,base

Author

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

Status

approved