A171903 Numbers m such that m and m+1 have at least two identical neighboring digits in their decimal representations.

99, 110, 111, 112, 113, 114, 115, 116, 117, 118, 199, 220, 221, 222, 223, 224, 225, 226, 227, 228, 299, 330, 331, 332, 333, 334, 335, 336, 337, 338, 399, 440, 441, 442, 443, 444, 445, 446, 447, 448, 499, 550, 551, 552, 553, 554, 555, 556, 557, 558, 599, 660

Offset: 1

Author

Reinhard Zumkeller, Feb 07 2010

Keywords

• base
• nonn
• look

Comments

a(n) + 1 = A171901(k) for some k;

A171902(a(n)) = 1.

Links

• R. Zumkeller, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A196368, A171901, A171904.

Programs

Haskell

import Data.List (elemIndices)
a171903 n = a171903_list !! (n-1)
a171903_list = elemIndices 0 $
               zipWith (+) a196368_list $ tail a196368_list
-- Reinhard Zumkeller, Jan 31 2014

Formula

A196368(a(n)) + A196368(a(n)+1) = 0. - Reinhard Zumkeller, Jan 31 2014