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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A125697 Table, T(n,k) is the number of categories with n morphisms and k objects. 2
1, 2, 1, 7, 3, 1, 35, 16, 3, 1, 228, 77, 20, 3, 1, 2237, 485, 111, 21, 3, 1, 31559 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is a two-dimensional Euler transform of A125699.

LINKS

Table of n, a(n) for n=1..22.

Eric Weisstein's World of Mathematics, Category

FORMULA

G.f. Product_{i=1}^{infinity} Product_{j=1}^{ceiling(i/2)} 1 / (1 - x^i y^j)^A125699(i,j).

T(n,k) = A125701(n-k) when k >= 2/3 n.

EXAMPLE

The table starts:

1

2,1

7,3,1

35,16,3,1

CROSSREFS

Cf. A125696 (row sums), A058129 (column 1), A125699, A125701, A125726.

Sequence in context: A197328 A136535 A091370 * A090699 A214550 A120903

Adjacent sequences:  A125694 A125695 A125696 * A125698 A125699 A125700

KEYWORD

tabl,hard,more,nonn

AUTHOR

Franklin T. Adams-Watters and Christian G. Bower, Jan 05 2007

STATUS

approved

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 June 19 02:31 EDT 2013. Contains 226386 sequences.