cp's OEIS Frontend

A072429 Numbers n for which there are exactly five k such that n = k + reverse(k).

%I A072429 #9 Jul 12 2019 20:18:37
%S A072429 55,154,505,525,545,565,585,605,625,645,665,685,1414,1434,1441,1454,
%T A072429 1474,1494,1514,1534,1554,1574,1594,2541,5005,6985,14014,14041,14241,
%U A072429 14441,14641,14841,15041,15241,15441,15641,15841,15994,18458,19558
%N A072429 Numbers n for which there are exactly five k such that n = k + reverse(k).
%C A072429 Subsequence of A067030. First term is A072041(5).
%C A072429 Contains 5*(10^k+1) for k>=1. - _Robert Israel_, Jul 12 2019
%H A072429 Robert Israel, <a href="/A072429/b072429.txt">Table of n, a(n) for n = 1..254</a>
%H A072429 <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a>
%e A072429 55 = k + reverse(k) for k = 14, 23, 32, 41, 50; 1441 = k + reverse(k) for k = 1040, 1130, 1220, 1310, 1400.
%p A072429 N:= 10^5:
%p A072429 revdigs:= proc(n) local L, i;
%p A072429   L:= convert(n, base, 10);
%p A072429   add(L[-i]*10^(i-1), i=1..nops(L))
%p A072429 end proc:
%p A072429 V:= Vector(N):
%p A072429 for x from 1 to N do
%p A072429   v:= x + revdigs(x);
%p A072429   if v <= N then V[v]:= V[v]+1 fi;
%p A072429 od:
%p A072429 select(t -> V[t]=5, [$1..N]); # Robert Israel, Jul 12 2019
%o A072429 (ARIBAS) var n,k,c,i,rev: integer; st,nst: string; end; m := 5; for n := 0 to 24600 do k := n div 2; c := 0; while k <= n and c < m + 1 do st := itoa(k); nst := ""; for i := 0 to length(st) - 1 do nst := concat(st[i],nst); end; rev := atoi(nst); if n = k + rev then inc(c); if k mod 10 <> 0 and k <> rev then inc(c); end; end; inc(k); end; if c = m then write(n,","); end; end;
%Y A072429 Cf. A067030, A072041.
%K A072429 base,nonn
%O A072429 1,1
%A A072429 _Klaus Brockhaus_, Jun 17 2002