cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

This page as a plain text file.
%I A225296 #22 Jan 13 2019 19:39:06
%S A225296 24,200,208,216,224,232,240,248,256,264,272,280,288,296,324,351,378,
%T A225296 448,500,648,2000,2008,2016,2024,2032,2040,2048,2056,2064,2072,2080,
%U A225296 2088,2096,2104,2112,2120,2128,2136,2144,2152,2160,2168,2176,2184,2192,2200,2208
%N A225296 Numbers divisible by their first digit cubed (excluding those whose first digit is 1).
%C A225296 Numbers where floor(n/10^floor(log(n)))^3 | n.
%H A225296 Christian N. K. Anderson, <a href="/A225296/b225296.txt">Table of n, a(n) for n = 1..10000</a>
%H A225296 Christian N. K. Anderson, <a href="/A225296/a225296_1.gif">Ulam Spiral</a> of first 10000 terms.
%e A225296 448 is divisible by 4^3.
%t A225296 dfdcQ[n_]:=Module[{fidn=IntegerDigits[n][[1]]},fidn!=1&&Divisible[ n,fidn^3]]; Select[Range[2500],dfdcQ] (* _Harvey P. Dale_, Jan 13 2019 *)
%o A225296 (R) x=0; y=rep(0,1000); len=0
%o A225296 firstdig<-function(x) as.numeric(substr(as.character(x),1,1))
%o A225296 isint<-function(x) x==as.integer(x)
%o A225296 while(len<1000) if((fd=firstdig((x=x+1)))>1) if(isint(x/fd^3)) y[(len=len+1)]=x
%Y A225296 Cf. A132359, A034709, A034837, A005349, A007602, A034838.
%K A225296 nonn,base
%O A225296 1,1
%A A225296 _Kevin L. Schwartz_ and _Christian N. K. Anderson_, May 04 2013