The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A022507 Describe previous term from the right (method A - initial term is 3). 10
 3, 13, 1311, 211311, 21132112, 122112132112, 122112131112212211, 2122112231131112212211, 21221122311321132221221112, 12312211321321121321132221221112 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Method A = 'frequency' followed by 'digit'-indication. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..21 Eric Weisstein's World of Mathematics, Look and Say Sequence Wikipedia, Look-and-say sequence FORMULA a(n+1) = A045918(A004086(a(n))). - Reinhard Zumkeller, Mar 02 2014 EXAMPLE E.g. the term after 1311 is obtained by saying "two 1's, one 3, one 1", which gives 211311. MATHEMATICA A022507[1]:=3; A022507[n_]:=A022507[n]=FromDigits[Flatten[{Length[#], First[#]}&/@Split[Reverse[IntegerDigits[A022507[n-1]]]]]]; Map[A022507, Range[15]] (* Peter J. C. Moses, Apr 22 2013 *) PROG (Haskell) a022507 n = a022507_list !! n a022507_list = iterate (a045918 . a004086) 3 -- Reinhard Zumkeller, Mar 02 2014 CROSSREFS Cf. A022506, A006711, A022482, A022508-A022513. Sequence in context: A006715 A177362 A138487 * A108583 A127855 A087333 Adjacent sequences:  A022504 A022505 A022506 * A022508 A022509 A022510 KEYWORD nonn,base,easy,nice AUTHOR EXTENSIONS More terms from Erich Friedman. STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 6 11:27 EDT 2020. Contains 333273 sequences. (Running on oeis4.)