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A240595 Look-and-Say table, where in row(n+1) the sorted list of distinct terms of row(n) is preceded by the list of numbers of their occurrences. 1
1, 1, 1, 2, 1, 1, 1, 1, 2, 3, 1, 1, 2, 2, 1, 1, 1, 2, 3, 3, 2, 1, 1, 2, 3, 2, 2, 2, 1, 2, 3, 1, 4, 1, 1, 2, 3, 3, 1, 1, 1, 1, 2, 3, 4, 4, 1, 2, 1, 1, 2, 3, 4, 3, 2, 1, 2, 1, 2, 3, 4, 2, 3, 2, 1, 1, 2, 3, 4, 2, 3, 2, 1, 1, 2, 3, 4, 2, 3, 2, 1, 1, 2, 3, 4, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

For n > 13: row(n) = row(13), see example.

LINKS

Table of n, a(n) for n=1..86.

Eric Weisstein's World of Mathematics, Look and Say Sequence

Wikipedia, Look-and-say sequence

EXAMPLE

.  1: [1] -> 1x1 -> [1 | 1] -> row(2)

.  2: [1,1] -> 2x1 -> [2 | 1] -> row(3)

.  3: [2,1] -> 1x1, 1x2 -> [1,1 | 1,2] -> row(4)

.  4: [1,1,1,2] -> 3x1, 1x2 -> [3,1 | 1,2] -> row(5)

.  5: [3,1,1,2] -> 2x1, 1x2, 1x3 -> [2,1,1 | 1,2,3] -> row(6)

.  6: [2,1,1,1,2,3] -> 3x1, 2x2, 1x3 -> [3,2,1 | 1,2,3] -> row(7)

.  7: [3,2,1,1,2,3] -> 2x1, 2x2, 2x3 -> [2,2,2 | 1,2,3] -> row(8)

.  8: [2,2,2,1,2,3] -> 1x1, 4x2, 1x3 -> [1,4,1 | 1,2,3] -> row(9)

.  9: [1,4,1,1,2,3] -> 3x1, 1x2, 1x3, 1x4 -> [3,1,1,1 | 1,2,3] -> row(10)

. 10: [3,1,1,1,1,2,3,4] -> 4x1, 1x2, 2x3, 1x4 -> [4,1,2,1 | 1,2,3,4]

. 11: [4,1,2,1,1,2,3,4] -> 3x1, 2x2, 1x3, 2x4 -> [3,2,1,2 | 1,2,3,4]

. 12: [3,2,1,2,1,2,3,4] -> 2x1, 3x2, 2x3, 1x4 -> [2,3,2,1 | 1,2,3,4]

. 13: [2,3,2,1,1,2,3,4] -> 2x1, 3x2, 2x3, 1x4 -> [2,3,2,1 | 1,2,3,4]

. 14: [2,3,2,1,1,2,3,4] = row(13).

PROG

(Haskell)

import Data.List (sort, group)

a240595 n k = a240595_tabf !! (n-1) !! (k-1)

a240595_row n = a240595_tabf !! (n-1)

a240595_tabf = iterate f [1] where

   f xs = concat [map length zss, map head zss]

          where zss = group $ sort xs

CROSSREFS

Cf. A034002.

Sequence in context: A303929 A303694 A194673 * A083671 A201913 A232463

Adjacent sequences:  A240592 A240593 A240594 * A240596 A240597 A240598

KEYWORD

nonn,tabf

AUTHOR

Reinhard Zumkeller, Apr 08 2014

STATUS

approved

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Last modified May 28 18:24 EDT 2022. Contains 354122 sequences. (Running on oeis4.)