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!)
A251815 Number of (n+2)X(4+2) 0..2 arrays with every row, column, diagonal or antidiagonal in each 3X3 subblock summing to a prime 1

%I #4 Dec 09 2014 11:26:09

%S 1215,1511,5401,22922,96649,409196,1741500,7424379,31630192,134638409,

%T 573239769,2441382476,10396957545,44272817726,188528190560,

%U 802834481337,3418801560572,14558580766123,61996115520891,264004067912028

%N Number of (n+2)X(4+2) 0..2 arrays with every row, column, diagonal or antidiagonal in each 3X3 subblock summing to a prime

%C Column 4 of A251819

%H R. H. Hardin, <a href="/A251815/b251815.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +6*a(n-2) +21*a(n-3) +53*a(n-4) +32*a(n-5) -61*a(n-6) -245*a(n-7) -323*a(n-8) +337*a(n-9) +944*a(n-10) +125*a(n-11) -1087*a(n-12) -852*a(n-13) +494*a(n-14) +889*a(n-15) +81*a(n-16) -280*a(n-17) -101*a(n-18) -17*a(n-19) -51*a(n-20) -9*a(n-21) +28*a(n-22) +a(n-23) +12*a(n-24) +7*a(n-25) -4*a(n-26) for n>28

%e Some solutions for n=4

%e ..1..1..1..1..1..0....1..0..1..1..1..0....1..0..1..1..1..1....1..0..1..1..1..1

%e ..1..1..1..0..1..1....1..1..1..1..1..1....1..1..1..0..1..1....1..1..1..1..1..1

%e ..1..0..1..1..1..1....1..1..1..1..1..1....1..1..1..1..1..1....1..1..1..1..1..1

%e ..1..1..1..1..1..1....1..1..1..1..1..1....0..1..1..1..0..1....1..1..0..1..1..1

%e ..1..1..1..1..1..1....0..1..1..1..1..0....1..1..1..1..1..1....1..1..1..1..0..1

%e ..1..1..1..1..1..0....1..0..1..1..0..1....1..0..1..1..1..0....1..0..1..1..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 09 2014

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 September 15 15:47 EDT 2024. Contains 375938 sequences. (Running on oeis4.)