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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A181194 Number of n X 7 matrices containing a permutation of 1..n*7 in increasing order rowwise, columnwise, diagonally and (downwards) antidiagonally. 2

%I #6 Feb 27 2018 05:32:39

%S 1,132,49100,25097600,14083834704,8092149471168,4673805856338368,

%T 2702482348019033600,1562998915785444034816,904016986809953084011520,

%U 522876616523380188491377664,302428597238403007787949047808

%N Number of n X 7 matrices containing a permutation of 1..n*7 in increasing order rowwise, columnwise, diagonally and (downwards) antidiagonally.

%C Column 7 of A181196.

%H R. H. Hardin, <a href="/A181194/b181194.txt">Table of n, a(n) for n=1..100</a>

%F Empirical: a(n) = 720*a(n-1) - 84448*a(n-2) + 1503360*a(n-3) - 17912224*a(n-4) - 318223104*a(n-5) + 564996096*a(n-6) + 270471168*a(n-7) - 11373824*a(n-8) + 65536*a(n-9).

%F Empirical g.f.: x*(1 - 588*x + 38508*x^2 - 610624*x^3 - 20571792*x^4 + 98269760*x^5 + 112896832*x^6 - 6488576*x^7 + 57344*x^8) / ((1 - 2*x)*(1 - 26*x + 512*x^2)*(1 - 114*x - 1156*x^2 + 8*x^3)*(1 - 578*x - 228*x^2 + 8*x^3)). - _Colin Barker_, Feb 27 2018

%e Some solutions for 4 X 7:

%e ..1..2..3..4..5..6..7....1..2..3..4..5..7.10....1..2..3..4..5..7.10

%e ..8..9.10.11.12.13.14....6..8..9.12.13.15.19....6..8..9.12.13.15.19

%e .15.16.17.18.19.20.21...11.14.17.18.20.22.24...11.14.17.18.20.22.25

%e .22.23.24.25.26.27.28...16.21.23.25.26.27.28...16.21.23.24.26.27.28

%Y Cf. A181196.

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 10 2010

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.

Last modified August 3 08:07 EDT 2024. Contains 374885 sequences. (Running on oeis4.)