A249855 Numbers <= 10^6 with valid Luhn mod 10 check digit, sorted first by check digit, then lexicographically.

0, 100040, 100180, 100230, 100370, 100420, 100560, 100610, 100750, 100800, 10090, 100990, 101030, 101170, 101220, 101360, 10140, 101410, 101550, 101600, 101790, 101840, 101980, 102020, 102160, 102210, 102350, 102400, 102590, 102640, 102780, 10280, 102830

Offset: 1

Author

Reinhard Zumkeller, Nov 08 2014

Keywords

• nonn
• base
• fini
• full
• look

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..100000
• Wikipedia, Luhn algorithm
• Index entries for sequences related to decimal expansion of n

Crossrefs

Cf. A093018, A249854.

Programs

Haskell

import Data.List (sortBy); import Data.Function (on)
a249855 n = a249855_list !! (n-1)
a249855_list = sortBy (compare `on` f) $ takeWhile (<= 10^6) a093018_list
               where f x = (head $ reverse ds, ds) where ds = show x