cp's OEIS Frontend

A225902 Numbers whose arithmetic derivatives are a permutation of their digits.

%I A225902 #9 May 09 2021 22:11:32
%S A225902 4,27,94,308,526,594,950,1208,1269,1647,2403,3125,5589,5643,5926,6934,
%T A225902 9369,10503,10568,11084,11284,12404,12447,13130,13500,14024,14769,
%U A225902 17469,17847,18036,20358,20547,20852,25569,27891,28647,29835,34803,36068,36180,36747
%N A225902 Numbers whose arithmetic derivatives are a permutation of their digits.
%C A225902 A051674 is a subsequence of this sequence.
%H A225902 Paolo P. Lava, <a href="/A225902/b225902.txt">Table of n, a(n) for n = 1..5000</a>
%e A225902 18036' = 36180, so 18036 is a term.
%e A225902 20852' = 22508, so 20852 is a term.
%e A225902 48872' = 74828, so 48872 is a term.
%p A225902 with(numtheory); A225902:= proc(i) local a,b,c,d,j,n,ok,p,pfs;
%p A225902 for n from 1 to i do b:=[]; c:=[];
%p A225902 a:=n*add(op(2,p)/op(1,p),p=ifactors(n)[2]);
%p A225902 while a>0 do b:=[op(b),a mod 10]; a:=trunc(a/10); od; a:=n;
%p A225902 while a>0 do c:=[op(c),a mod 10]; a:=trunc(a/10); od; d:=0;
%p A225902 if nops(b)=nops(c) then b:=sort(b); c:=sort(c); b:=b-c; ok:=1; for j from 1 to nops(b) do if b[j]<>0  then ok:=0; break; fi; od; if ok=1 then print(n); fi; fi;
%p A225902 od; end; A225902(10000);
%Y A225902 Cf. A003415, A051674.
%K A225902 nonn,base
%O A225902 1,1
%A A225902 _Paolo P. Lava_, May 20 2013