A252575 Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.
702, 843, 1069, 1694, 2985, 5401, 9936, 18972, 36144, 68328, 132259, 254014, 483085, 937293, 1802438, 3435781, 6666327, 12816791, 24467952, 47451918, 91181264, 174286544, 337798170, 648685210, 1241316959, 2404367968, 4614248202
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..3..2..1..3..2....3..1..1..0..0..1....2..3..2..2..3..2....2..2..2..3..0..3 ..0..0..2..0..0..1....3..1..2..2..1..2....0..0..1..0..0..2....1..1..0..1..1..3 ..2..0..0..2..0..0....2..2..1..2..2..1....2..0..0..2..0..0....0..0..2..0..3..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 25*a(n-3) +a(n-4) -239*a(n-6) -23*a(n-7) +1103*a(n-9) +192*a(n-10) -2670*a(n-12) -696*a(n-13) +3918*a(n-15) +1086*a(n-16) -4034*a(n-18) -1050*a(n-19) +3218*a(n-21) +848*a(n-22) -1969*a(n-24) -472*a(n-25) +889*a(n-27) +177*a(n-28) -303*a(n-30) -63*a(n-31) +63*a(n-33) for n>43
Comments