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 A022515 Describe previous term from the right (method B - initial term is 4). 5
 4, 41, 1141, 114112, 21124112, 211241211221, 112212211141211221, 1122122111411322112212, 21112212223112411322112212, 21112212223112412112312311221321 (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 1141 is obtained by saying "1 once, 4 once, 1 twice", which gives 114112. MATHEMATICA A022515[1]:=4; A022515[n_]:=A022515[n]=FromDigits[Flatten[{First[#], Length[#]}&/@Split[Reverse[IntegerDigits[A022515[n-1]]]]]]; Map[A022515, Range[15]] (* Peter J. C. Moses, Apr 22 2013 *) PROG (Haskell) import Data.List (group, transpose) a022515 n = a022515_list !! n a022515_list = 4 : f [4] :: [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, A022514-A022520. Sequence in context: A284276 A327026 A244751 * A172496 A059730 A006825 Adjacent sequences: A022512 A022513 A022514 * A022516 A022517 A022518 KEYWORD nonn,base,easy,nice AUTHOR N. J. A. Sloane EXTENSIONS More terms from Patrick De Geest, Jun 15 1999 STATUS approved

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Last modified July 22 09:18 EDT 2024. Contains 374485 sequences. (Running on oeis4.)