A132285 Mirror odd numbers.

11, 33, 55, 77, 99, 1001, 1111, 1221, 1331, 1441, 1551, 1661, 1771, 1881, 1991, 3003, 3113, 3223, 3333, 3443, 3553, 3663, 3773, 3883, 3993, 5005, 5115, 5225, 5335, 5445, 5555, 5665, 5775, 5885, 5995, 7007, 7117, 7227, 7337, 7447, 7557, 7667, 7777, 7887

Offset

1,1

Comments

Mirror numbers have even number of digits with property that left half digits is mirror of right half digits.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..555

Formula

A005408 INTERSECT A001637 INTERSECT A002113. - R. J. Mathar, Aug 22 2007

Mathematica

monQ[n_]:=Module[{len=IntegerLength[n], idn=IntegerDigits[n]}, EvenQ[ len] &&Take[idn, len/2]==Reverse[Take[idn, -len/2]]]; Select[Range[11, 9999, 2], monQ] (* Harvey P. Dale, Apr 18 2014 *)

Prog

(PARI) isok(n) = {if (n % 2 == 0, return (0)); d = digits(n); if (#d % 2 == 1, return (0)); for (i=1, #d/2, if (d[i] != d[#d-i+1], return (0)); ); return (1); } \\ Michel Marcus, Nov 05 2013

Crossrefs

Cf. A005408, A001637, A002113, A132286, A132288.

Sequence in context: A022671 A029516 A061833 * A249166 A296543 A152740

Adjacent sequences: A132282 A132283 A132284 * A132286 A132287 A132288

Keyword

nonn,base

Author

Artur Jasinski, Aug 16 2007

Status

approved