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

Author

Antti Karttunen, Jan 02 2007

Keywords

• nonn

Comments

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

Examples

			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))).

Formula

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