|
%I #19 Oct 19 2016 07:59:15
%S 2,4,6,8,22,44,66,88,110,132,198,202,212,220,222,231,232,242,252,262,
%T 264,272,282,292,297,330,396,404,414,424,434,440,444,454,462,464,474,
%U 484,494,495,550,594,606,616,626,636,646,656,660,666,676,686,693,696,770
%N Numbers such that n+R(n) | n*R(n), where R(n) is the digits reverse of n.
%C This sequence contains all positive terms of A029951. So the sequence is infinite. - _Altug Alkan_, Oct 07 2016
%H Paolo P. Lava, <a href="/A277258/b277258.txt">Table of n, a(n) for n = 1..1000</a>
%e R(132) = 231, (132 * 231) / (132 + 231) = 30492 / 363 = 84.
%p R:=proc(w) local x, y, z; x:=w; y:=0; for z from 1 to ilog10(x)+1 do y:=10*y+(x mod 10); x:=trunc(x/10); od; y; end: P:= proc(q) local n; for n from 1 to q do if type(n*R(n)/(n+R(n)),integer) then print(n); fi; od; end: P(10^4);
%t Select[Range@ 770, Function[r, Mod[# r, # + r] == 0]@ FromDigits@ Reverse@ IntegerDigits@ # &] (* _Michael De Vlieger_, Oct 14 2016 *)
%o (PARI) R(n) = eval(concat(Vecrev(Str(n))));
%o isok(n) = n*R(n) % (n+R(n)) == 0; \\ _Michel Marcus_, Oct 15 2016
%Y Cf. A004086, A029951, A056964, A061205, A131058.
%K nonn,easy,base
%O 1,1
%A _Paolo P. Lava_, Oct 07 2016
|
