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 A022514 Describe previous term from the right (method B - initial term is 3). 9
 3, 31, 1131, 113112, 21123112, 211231211221, 112212211131211221, 1122122111311322112212, 21112212223112311322112212, 21112212223112312112312311221321 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Method B = 'digit'-indication followed by 'frequency'. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..21 EXAMPLE The term after 1131 is obtained by saying "1 once, 3 once, 1 twice", which gives 113112. MATHEMATICA A022514[1]:=3; A022514[n_]:=A022514[n]=FromDigits[Flatten[{First[#], Length[#]}&/@Split[Reverse[IntegerDigits[A022514[n-1]]]]]]; Map[A022514, Range[15]] (* Peter J. C. Moses, Apr 22 2013 *) PROG (Haskell) import Data.List (group, transpose) a022514 n = a022514_list !! n a022514_list = 3 : f [3] :: [Integer] where    f xs = (read \$ concatMap show ys) : f ys where           ys = concat \$ transpose [map head zss, map length zss]           zss = reverse \$ group xs -- Reinhard Zumkeller, Jan 26 2014 CROSSREFS Cf. A022481, A022488, A022515-A022520. Sequence in context: A227787 A274592 A219266 * A094579 A029729 A319253 Adjacent sequences:  A022511 A022512 A022513 * A022515 A022516 A022517 KEYWORD nonn,base,easy,nice AUTHOR EXTENSIONS More terms from Patrick De Geest, Jun 15 1999 STATUS approved

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Last modified February 29 08:26 EST 2020. Contains 332355 sequences. (Running on oeis4.)