login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A107321 a(n)=Sum(i+j+k+l+...+r+s=n) A005316(i)*A005316(j)*...*A005316(s) and the ordered partition of n runs over all odd i, all even j,k,.., r, all i,j,...,r,s>=1. 1
1, 1, 2, 3, 8, 14, 42, 79, 254, 506, 1702, 3548, 12320, 26666, 94794, 211751, 766362, 1758352, 6453812, 15150922, 56238710, 134659120 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

A lower bound to A076876. a(n) counts the cases where all crossings k are East of the crossings i, all crossings l East of the crossings j etc. Some backwinding interlaced crossings are counted in A076876(n) but not here.

CROSSREFS

Sequence in context: A049344 A080877 A007165 * A005316 A076876 A124495

Adjacent sequences:  A107318 A107319 A107320 * A107322 A107323 A107324

KEYWORD

nonn

AUTHOR

R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 06 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 08:13 EST 2012. Contains 205893 sequences.