A250729 T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.
9, 22, 18, 50, 46, 33, 114, 110, 85, 58, 257, 257, 208, 144, 99, 579, 596, 496, 365, 230, 166, 1302, 1376, 1158, 885, 600, 350, 275, 2927, 3173, 2699, 2092, 1500, 942, 513, 452, 6578, 7310, 6257, 4889, 3605, 2434, 1418, 728, 739, 14782, 16838, 14520, 11377, 8514
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..0..0..0..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0 ..1..0..1..0..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0 ..0..1..0..1..0....0..1..0..0..0....0..0..0..0..0....0..0..0..0..0 ..1..0..1..0..1....1..0..1..0..1....0..0..0..0..0....0..0..0..0..1 ..0..1..0..1..0....0..1..0..1..0....0..1..0..1..0....0..1..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..1860
Crossrefs
Column 1 is A192760(n+2)
Formula
Empirical for column k:
k=1: a(n) = 3*a(n-1) -2*a(n-2) -a(n-3) +a(n-4)
k=2: a(n) = 4*a(n-1) -5*a(n-2) +5*a(n-4) -4*a(n-5) +a(n-6); also a polynomial of degree 4 plus a quasipolynomial of degree 0 with period 2
k=3: a(n) = 4*a(n-1) -5*a(n-2) +5*a(n-4) -4*a(n-5) +a(n-6); also a polynomial of degree 4 plus a quasipolynomial of degree 0 with period 2
k=4: a(n) = 5*a(n-1) -9*a(n-2) +5*a(n-3) +5*a(n-4) -9*a(n-5) +5*a(n-6) -a(n-7) for n>8; also a polynomial of degree 5 plus a quasipolynomial of degree 0 with period 2 for n>1
k=5: [order 8; also a polynomial of degree 6 plus a quasipolynomial of degree 0 with period 2] for n>10
k=6: [order 9; also a polynomial of degree 7 plus a quasipolynomial of degree 0 with period 2] for n>14
k=7: [order 10; also a polynomial of degree 8 plus a quasipolynomial of degree 0 with period 2] for n>17
Empirical for row n:
n=1: a(n) = 3*a(n-1) -a(n-2) -2*a(n-3) +a(n-4)
n=2: a(n) = 2*a(n-1) +2*a(n-2) -3*a(n-3) for n>4
n=3: a(n) = 4*a(n-1) -2*a(n-2) -9*a(n-3) +12*a(n-4) -2*a(n-5) -3*a(n-6) +a(n-7) for n>8
n=4: [order 7] for n>9
n=5: [order 9] for n>12
n=6: [order 11] for n>15
n=7: [order 14] for n>19
Comments