A252509 Number of (n+2) X (3+2) 0..3 arrays with every 3 X 3 subblock row and column sum equal to 0 2 5 6 or 7 and every 3 X 3 diagonal and antidiagonal sum not equal to 0 2 5 6 or 7.

2055, 3980, 11476, 28877, 83016, 252551, 767176, 2326656, 7067545, 21555438, 65998872, 202139805, 619664176, 1902757710, 5844530563, 17960909526, 55236099834, 169893963331, 522684802558, 1608599668122, 4950903773021

Offset

1,1

Comments

Column 3 of A252514.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -a(n-2) +35*a(n-3) -93*a(n-4) +31*a(n-5) -442*a(n-6) +939*a(n-7) -313*a(n-8) +2607*a(n-9) -3585*a(n-10) +1195*a(n-11) -8743*a(n-12) +6714*a(n-13) -2238*a(n-14) +21413*a(n-15) -14283*a(n-16) +4761*a(n-17) -46814*a(n-18) +26640*a(n-19) -8880*a(n-20) +86138*a(n-21) -23769*a(n-22) +7923*a(n-23) -125344*a(n-24) +19671*a(n-25) -6557*a(n-26) +157146*a(n-27) -12624*a(n-28) +4208*a(n-29) -170762*a(n-30) -16695*a(n-31) +5565*a(n-32) +140413*a(n-33) +53586*a(n-34) -17862*a(n-35) -68838*a(n-36) -37272*a(n-37) +12424*a(n-38) +13448*a(n-39) +768*a(n-40) -256*a(n-41) -256*a(n-42) for n>47.

Example

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

Crossrefs

Cf. A252514.

Sequence in context: A020400 A068723 A252187 * A250331 A234772 A168227

Adjacent sequences: A252506 A252507 A252508 * A252510 A252511 A252512

Keyword

nonn

Author

R. H. Hardin, Dec 18 2014

Status

approved