login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A252151 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7 1

%I

%S 1945,1874,1898,2702,4732,8769,16786,32653,64082,126281,249972,496351,

%T 987018,1965441,3918468,7816699,15602898,31159889,62243052,124369539,

%U 248564606,496831189,993205780,1985726667,3970284238,7938763405

%N Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7

%C Column 2 of A252157

%H R. H. Hardin, <a href="/A252151/b252151.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) -2*a(n-2) +7*a(n-3) -18*a(n-4) +5*a(n-5) -8*a(n-6) +21*a(n-7) +34*a(n-8) -31*a(n-9) +16*a(n-10) -103*a(n-11) +63*a(n-12) -10*a(n-13) +58*a(n-14) -6*a(n-15) -28*a(n-16) +8*a(n-17) -24*a(n-18) +16*a(n-19) for n>27

%e Some solutions for n=4

%e ..3..3..3..3....3..3..3..3....0..2..0..3....1..1..2..1....3..3..3..3

%e ..2..0..2..3....0..2..0..2....2..0..2..2....0..2..0..3....3..1..0..3

%e ..0..2..0..2....2..0..2..0....3..2..3..3....3..2..3..0....3..0..2..3

%e ..2..0..2..0....0..2..0..2....3..2..3..3....1..0..1..1....3..1..0..3

%e ..0..2..0..3....2..0..2..3....2..0..2..2....0..2..0..3....3..3..3..3

%e ..2..0..3..1....3..3..3..3....0..2..0..3....3..2..3..0....3..0..1..3

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 14 2014

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 5 19:02 EDT 2020. Contains 335473 sequences. (Running on oeis4.)