A110745 - OEIS

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

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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.