A137239 a(n)= number of Catalan numbers with n digits.

4, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2

Offset

1,1

Links

J. Mulder, Table of n, a(n) for n = 1..12034

Example

1-digit Catalan numbers are 1,1,2,5 so a(1)=4
2-digits Catalan numbers are 14,24 so a(2)=2

Crossrefs

Cf. A000108.

Sequence in context: A282698 A136709 A254969 * A136714 A280135 A297825

Adjacent sequences: A137236 A137237 A137238 * A137240 A137241 A137242

Keyword

nonn,base,easy

Author

Ctibor O. Zizka, Mar 09 2008

Extensions

Corrected and extended by Sean A. Irvine, Feb 07 2010

Status

approved