A067031 Numbers that are not of the form k + reverse(k) for any k.

1, 3, 5, 7, 9, 13, 15, 17, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87

Offset: 0

Author

Klaus Brockhaus, Dec 29 2001

Keywords

• base
• easy
• nonn

Examples

			3 belongs to the sequence since there is no k such that k + reverse(k) = 3.
		

Links

• Daniel Starodubtsev, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A056964.

Complement of A067030.

Cf. A033865, A067030, A067032, A067033, A067034.

Programs

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);

Mathematica

Module[{nn=100,rd},rd=Union[Table[n+FromDigits[ Reverse[ IntegerDigits[ n]]],{n,nn}]];Complement[Range[nn],rd]] (* Harvey P. Dale, Dec 16 2013 *)