A252452 Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 2 4 6 or 7

323, 959, 3366, 11334, 38966, 134907, 464384, 1603397, 5553753, 19211480, 66422368, 229808142, 795271777, 2751760322, 9521215485, 32945797509, 114006440916, 394517543590, 1365232224566, 4724489737361, 16349870593488

Offset

1,1

Comments

Column 3 of A252457

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -8*a(n-2) +31*a(n-3) -46*a(n-4) -30*a(n-5) -238*a(n-6) -338*a(n-7) +318*a(n-8) +1332*a(n-9) +3970*a(n-10) +3841*a(n-11) -2401*a(n-12) -15360*a(n-13) -24500*a(n-14) -6584*a(n-15) +32113*a(n-16) +50465*a(n-17) +6658*a(n-18) -54545*a(n-19) -40309*a(n-20) +34108*a(n-21) +92882*a(n-22) +54935*a(n-23) -66171*a(n-24) -137823*a(n-25) -87689*a(n-26) +35941*a(n-27) +110894*a(n-28) +83622*a(n-29) +8828*a(n-30) -42389*a(n-31) -45791*a(n-32) -24569*a(n-33) -3451*a(n-34) +9236*a(n-35) +12522*a(n-36) +9282*a(n-37) +3964*a(n-38) +40*a(n-39) -1136*a(n-40) -1008*a(n-41) -440*a(n-42) -144*a(n-43) -16*a(n-44) for n>47

Example

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

Crossrefs

Sequence in context: A083138 A121209 A065884 * A202610 A094394 A296973

Adjacent sequences: A252449 A252450 A252451 * A252453 A252454 A252455

Keyword

nonn

Author

R. H. Hardin, Dec 17 2014

Status

approved