A110745 a(n) is a number such that if odd positioned digits are deleted one gets n and if even positioned digits are deleted one gets n reversed. Counting is from the LSB side. The position of LSB is one.

11, 22, 33, 44, 55, 66, 77, 88, 99, 1001, 1111, 1221, 1331, 1441, 1551, 1661, 1771, 1881, 1991, 2002, 2112, 2222, 2332, 2442, 2552, 2662, 2772, 2882, 2992, 3003, 3113, 3223, 3333, 3443, 3553, 3663, 3773, 3883, 3993, 4004, 4114, 4224, 4334, 4444, 4554

Offset

1,1

Comments

Except for initial 0, rearrangement of numbers in A056524. They first differ at a(101) = 110011, while A056524(101) = 101101. If n has digits d_1 d_2 ... d_k, permute them to d_1 d_k d_2 d_{k-1} ... d_{floor(k/2)+1} and use that as index to A056524. - Franklin T. Adams-Watters, Jun 20 2006

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..9999

Example

a(12) = 1221, deleting the LSB and the third digit 2 we get 12, deleting second and fourth digit we get 21.

Prog

(Haskell)
import Data.List (transpose)
a110745 n = read (concat $ transpose [ns, reverse ns]) :: Integer
            where ns = show n
-- Reinhard Zumkeller, Feb 14 2015

Crossrefs

Cf. A045918.

Cf. A056524, A031298.

Sequence in context: A272655 A333440 A056524 * A280826 A020338 A052191

Adjacent sequences: A110742 A110743 A110744 * A110746 A110747 A110748

Keyword

base,nonn

Author

Amarnath Murthy, Aug 10 2005

Extensions

More terms from Franklin T. Adams-Watters, Jun 20 2006

Status

approved