A252642 Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 3 4 6 or 7

687, 1684, 4026, 8253, 22701, 56953, 121016, 345360, 878052, 1896105, 5611265, 14356645, 31417221, 96208961, 247141229, 546972786, 1726721164, 4448939128, 9937685585, 32176231897, 83097996347, 186944826455, 617389289663

Offset

1,1

Comments

Row 2 of A252640

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 86*a(n-3) -3182*a(n-6) +66973*a(n-9) -895271*a(n-12) +8064140*a(n-15) -50867891*a(n-18) +231279187*a(n-21) -776462668*a(n-24) +1968180875*a(n-27) -3848275417*a(n-30) +5915127032*a(n-33) -7240426796*a(n-36) +7089509055*a(n-39) -5534672806*a(n-42) +3401054768*a(n-45) -1598881704*a(n-48) +548907804*a(n-51) -124335864*a(n-54) +15500160*a(n-57) -777600*a(n-60) for n>63

Example

Some solutions for n=4
..0..2..2..3..2..2....0..1..3..0..1..3....1..0..3..1..3..3....3..1..3..0..1..3
..2..3..2..2..3..2....1..1..2..1..1..2....2..3..2..2..3..2....0..3..1..3..3..1
..0..3..1..0..3..1....1..3..3..1..0..3....2..2..0..2..2..3....2..1..1..2..1..1
..3..2..2..0..2..2....3..1..3..3..0..3....1..3..0..1..3..3....0..1..3..3..1..0

Crossrefs

Sequence in context: A101944 A045150 A296811 * A252084 A211162 A235851

Adjacent sequences: A252639 A252640 A252641 * A252643 A252644 A252645

Keyword

nonn

Author

R. H. Hardin, Dec 19 2014

Status

approved