A252001 Lexicographically earliest permutation of the positive integers, such that a carry occurs when adjacent terms are added in decimal representation.
1, 9, 2, 8, 3, 7, 4, 6, 5, 15, 16, 14, 17, 13, 18, 12, 19, 11, 29, 21, 39, 22, 28, 23, 27, 24, 26, 25, 35, 36, 34, 37, 33, 38, 32, 48, 42, 49, 31, 59, 41, 60, 40, 61, 43, 47, 44, 46, 45, 55, 50, 51, 52, 53, 54, 56, 57, 58, 62, 63, 64, 65, 66, 67, 68, 69, 70
Offset: 1
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
- Eric Weisstein's World of Mathematics, Carry
- Wikipedia, Carry (arithmetic)
- Index entries for sequences that are permutations of the natural numbers
Crossrefs
Programs
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Haskell
import Data.List (delete) a252001 n = a252001_list !! (n-1) a252001_list = 1 : f [1] (drop 2 a031298_tabf) where f xs zss = g zss where g (ds:dss) = if any (> 9) $ zipWith (+) xs ds then (foldr (\d v -> 10 * v + d) 0 ds) : f ds (delete ds zss) else g dss
Comments