A125887 a(1) = 1, a(n) = smallest positive number b not among a(1)..a(n-1) and not a multiple of 10 such that the first digit of b = the last digit of a(n-1).

1, 11, 12, 21, 13, 31, 14, 41, 15, 51, 16, 61, 17, 71, 18, 81, 19, 91, 101, 102, 22, 23, 32, 24, 42, 25, 52, 26, 62, 27, 72, 28, 82, 29, 92, 201, 103, 33, 34, 43, 35, 53, 36, 63, 37, 73, 38, 83, 39, 93, 301, 104, 44, 45, 54, 46, 64, 47, 74, 48, 84, 49, 94, 401, 105, 55, 56, 65

Offset: 1

Author

Zak Seidov, Dec 13 2006

Keywords

• base
• nonn
• look

Comments

A dyslexic person might have trouble distinguishing this sequence from A125886!

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A125886.

Cf. A000030, A010879.

Programs

Haskell

a125887 n = a125887_list !! (n-1)
a125887_list = 1 : f '1' (filter ((> 0) . (`mod` 10)) [11..]) where
   f d zs = y : f (last $ show y) (xs ++ ys) where
       (xs, y:ys) = span ((/= d) . head . show) zs
-- Reinhard Zumkeller, Jul 06 2011