Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A034731
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A034731 Dirichlet convolution of b_n=1 with Catalan numbers. +0
7
1, 2, 3, 7, 15, 46, 133, 436, 1433, 4878, 16797, 58837, 208013, 743034, 2674457, 9695281, 35357671, 129646266, 477638701, 1767268073, 6564120555, 24466283818, 91482563641, 343059672916, 1289904147339, 4861946609466 (list; graph; listen)
OFFSET

1,2

COMMENT

Also number of objects fixed by permutations A057509/A057510 (induced by shallow rotation of general parenthesizations/plane trees).

FORMULA

a(n) = Sum_{d divides n} C(d-1) where C() are the Catalan numbers (A000108).

CROSSREFS

Occurs for first time in A073202 as row 16. Cf. A057546, A000108.

Sequence in context: A039826 A161746 A045629 this_sequence A110888 A058698 A058699

Adjacent sequences: A034728 A034729 A034730 this_sequence A034732 A034733 A034734

KEYWORD

nonn

AUTHOR

Erich Friedman (erich.friedman(AT)stetson.edu). More comments from Antti Karttunen (my_firstname.my_surname(AT)iki.fi) Jan 03 2003.

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


AT&T Labs Research