A045981 Describe all the previous terms!.

1, 11, 1121, 1121211211, 112121121121121112211221, 112121121121121112211221211211122112211221123122212211

Offset: 1

Author

Anthony Joseph Splendora

Keywords

• nonn
• easy
• base
• nice

Comments

Previous terms are described one by one in succession. Next terms are 118, 256, 564 and 1262 digits long.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..9
• Eric Weisstein's World of Mathematics, Look and Say Sequence
• Wikipedia, Look-and-say sequence

Crossrefs

Cf. A005150, A045982.

Cf. A045918.

Programs

Haskell

a045981 n = a045981_list !! (n-1)
a045981_list = 1 : f 1 [] where
   f x zs = y : f y zs' where
     y = read (concatMap show zs')
     zs' = zs ++ [a045918 x]
-- Reinhard Zumkeller, Feb 28 2014

Extensions

More terms from Patrick De Geest, Jun 15 1999