|
|
A252215
|
|
Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 2 5 6 or 7
|
|
1
|
|
|
3147, 2836, 10486, 44776, 188866, 801122, 3410786, 14539238, 61939226, 263654432, 1122558798, 4780929468, 20360099382, 86698049968, 369189620578, 1572170465502, 6694947958402, 28509673198294, 121405330624876
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
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>29
|
|
EXAMPLE
|
Some solutions for n=4
..1..1..1..1..1..1....3..3..3..3..3..3....1..1..1..1..1..2....1..1..1..1..1..2
..1..1..2..1..1..2....3..2..3..3..3..2....1..1..1..1..1..1....1..2..1..1..1..1
..1..1..1..1..1..1....3..3..3..3..3..3....1..1..1..1..1..1....1..1..1..1..1..1
..1..1..1..1..1..1....3..3..2..3..3..3....1..2..1..1..2..1....1..1..1..1..1..1
..1..1..1..1..1..2....3..3..3..3..3..3....1..1..1..1..1..1....1..1..1..1..1..1
..1..1..1..1..1..1....3..3..3..3..3..2....2..1..1..1..1..2....1..1..1..2..1..1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|