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.
%I A067031 #20 Apr 19 2025 14:38:44
%S A067031 1,3,5,7,9,13,15,17,19,20,21,23,24,25,26,27,28,29,30,31,32,34,35,36,
%T A067031 37,38,39,40,41,42,43,45,46,47,48,49,50,51,52,53,54,56,57,58,59,60,61,
%U A067031 62,63,64,65,67,68,69,70,71,72,73,74,75,76,78,79,80,81,82,83,84,85,86,87
%N A067031 Numbers that are not of the form k + reverse(k) for any k.
%H A067031 Daniel Starodubtsev, <a href="/A067031/b067031.txt">Table of n, a(n) for n = 0..10000</a>
%e A067031 3 belongs to the sequence since there is no k such that k + reverse(k) = 3.
%t A067031 Module[{nn=100,rd},rd=Union[Table[n+FromDigits[ Reverse[ IntegerDigits[ n]]],{n,nn}]];Complement[Range[nn],rd]] (* _Harvey P. Dale_, Dec 16 2013 *)
%o A067031 (ARIBAS) function a067031(a,b: integer); var k,n,i,rev: integer; test: boolean; st,nst: string; begin for n := a to b do k := 0; test := 1; while test and k <= n 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 test := 0; else inc(k); end; end; if k > n then write(n,","); end; end; end; a067031(0,100);
%Y A067031 Cf. A056964.
%Y A067031 Complement of A067030.
%Y A067031 Cf. A033865, A067030, A067032, A067033, A067034.
%K A067031 base,easy,nonn
%O A067031 0,2
%A A067031 _Klaus Brockhaus_, Dec 29 2001