login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A247597 Number of nonisomorphic binary n X n matrices with four 1's per column under row and column permutations. 5

%I #35 May 24 2018 15:58:33

%S 1,7,132,6178,594203,85820809,16341829155,3875736708590,

%T 1112175913348040,378860991866916370,151006214911844288232,

%U 69600017255860985666964,36729204987785981237238642,22003003913198378660826731007,14851323097928973689736994569534

%N Number of nonisomorphic binary n X n matrices with four 1's per column under row and column permutations.

%H Andrew Howroyd, <a href="/A247597/b247597.txt">Table of n, a(n) for n = 4..40</a>

%H StackExchange, <a href="http://math.stackexchange.com/questions/616834/">How many arrays with crossed cells, order of rows/columns irrelevant</a>, Dec 13 2013

%p seq(matrix_marks(n,4), n=3..15); # Using the uploaded program to A247417

%o (PARI) \\ See A304942 for Blocks

%o a(n) = Blocks(n, n, 4); \\ _Andrew Howroyd_, May 24 2018

%Y Column k=4 of A304942.

%Y Cf. A247417, A247596, A247598.

%K nonn

%O 4,2

%A _Marko Riedel_, Sep 21 2014

%E Terms a(16) and beyond from _Andrew Howroyd_, May 24 2018

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 03:51 EDT 2024. Contains 371264 sequences. (Running on oeis4.)