A262472 T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with each row divisible by 3 and each column divisible by 5, read as a binary number with top and left being the most significant bits.
1, 1, 2, 1, 3, 4, 1, 6, 9, 7, 1, 11, 36, 17, 13, 1, 22, 121, 115, 37, 26, 1, 43, 484, 457, 469, 107, 52, 1, 86, 1849, 3055, 2413, 2622, 321, 103, 1, 171, 7396, 16081, 30229, 22907, 15732, 865, 205, 1, 342, 29241, 107731, 234421, 552430, 239281, 85723, 2449, 410, 1
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..0..0..0..0....0..0..0..0..0....0..1..1..0..0....0..1..0..0..1 ..0..1..0..0..1....0..1..1..0..0....0..1..0..0..1....0..0..0..1..1 ..0..0..0..0..0....0..1..0..0..1....0..1..1..1..1....0..1..0..0..1 ..0..1..0..0..1....0..1..1..0..0....0..1..0..0..1....0..0..0..1..1 ..0..0..0..0..0....0..1..0..0..1....0..0..0..1..1....0..0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..112
Formula
Empirical for column k:
k=1: a(n) = 3*a(n-1) -3*a(n-2) +3*a(n-3) -2*a(n-4)
k=2: [order 8]
k=3: [order 15]
k=4: [order 73]
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 2*a(n-1) +a(n-2) -2*a(n-3)
n=3: a(n) = 4*a(n-1) +5*a(n-2) -20*a(n-3) -4*a(n-4) +16*a(n-5)
n=4: [order 13]
n=5: [order 33]
n=6: [order 67]
Comments