A057515 - OEIS

%I #11 Aug 03 2017 00:42:04

%S 0,1,2,1,3,2,2,1,1,4,3,3,2,2,3,2,2,1,1,2,1,1,1,5,4,4,3,3,4,3,3,2,2,3,

%T 2,2,2,4,3,3,2,2,3,2,2,1,1,2,1,1,1,3,2,2,1,1,2,1,1,1,2,1,1,1,1,6,5,5,

%U 4,4,5,4,4,3,3,4,3,3,3,5,4,4,3,3,4,3,3,2,2,3,2,2,2,4,3,3,2,2,3,2,2,2,3,2,2

%N Number of separate "mountains" in mountain ranges encoded by A014486, number of bottom branches (trunks) in the corresponding rooted plane trees, i.e., the degree of the root node.

%C This sequence is produced when the function 'length' (present in programming languages like Lisp, Scheme, Prolog and Haskell) acts on symbolless S-expressions encoded by A014486/A063171.

%H A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (Includes the complete Scheme program for computing this sequence)

%H <a href="/index/Li#ListFunsOfLisp">Index entries for the sequences induced by list functions of Lisp</a>

%Y a(n) gives the first digit of A071153(n).

%K nonn

%O 0,3

%A _Antti Karttunen_, Sep 03 2000