A126307 a(n) is the length of the leftmost ascent (i.e., height of the first peak) in the n-th Dyck path encoded by A014486(n).

0, 1, 1, 2, 1, 1, 2, 2, 3, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

0,4

Comments

In other words, this sequence gives the number of leading 1's in the terms of A063171.

Links

Table of n, a(n) for n=0..101.

Formula

a(n) = A090996(A014486(n)).

Example

A014486(20) = 228 (11100100 in binary), encodes the following Dyck path:
    /\
   /  \/\
  /      \
and the first rising (left-hand side) slope has length 3, thus a(20)=3.

Crossrefs

a(n) = A099563(A071156(n)) = A057515(A125985(n)) = A080237(A057164(n)) = A057515(A057504(A057164(n))).

Sequence in context: A029272 A153904 A128762 * A320838 A092332 A092334

Adjacent sequences: A126304 A126305 A126306 * A126308 A126309 A126310

Keyword

nonn

Author

Antti Karttunen, Jan 02 2007

Status

approved