A072427 Numbers n for which there is a unique k such that n = k + reverse(k).

0, 2, 4, 6, 8, 10, 11, 12, 14, 16, 18, 101, 141, 161, 181, 198, 201, 221, 241, 261, 281, 1001, 1818, 1838, 1858, 1878, 1898, 1918, 1938, 1958, 1978, 1998, 2981, 10001, 10201, 10401, 10601, 10801, 11001, 11201, 11401, 11601, 11801, 18018, 19998

Offset

1,2

Comments

Subsequence of A067030. First term is A072041(1). A068065 is a subsequence of this sequence.

Links

T. D. Noe, Table of n, a(n) for n = 1..123

Index entries for sequences related to Reverse and Add!

Example

18 = 9 + 9; 261 = 180 + 081; 11401 = 10700 + 00701.

Mathematica

revAdd[n_] := n + FromDigits[Reverse[IntegerDigits[n]]]; ra=Table[revAdd[n], {n, 0, 10^5}]; t=Sort[Tally[ra]]; First /@ Select[t, #[[2]] == 1 && #[[1]] <= Length[ra] &]

Prog

(ARIBAS) var n, k, c, i, rev: integer; st, nst: string; end; m := 1; for n := 0 to 29000 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;

Crossrefs

Cf. A067030, A068065, A072041, A072040, A071914.

Sequence in context: A154809 A153170 A067030 * A337430 A050420 A214671

Adjacent sequences: A072424 A072425 A072426 * A072428 A072429 A072430

Keyword

base,nonn

Author

Klaus Brockhaus, Jun 17 2002

Status

approved