A250432 T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with nondecreasing sum of every two consecutive values in every row and column.
16, 36, 36, 81, 108, 81, 144, 324, 324, 144, 256, 720, 1296, 720, 256, 400, 1600, 3600, 3600, 1600, 400, 625, 3000, 10000, 12000, 10000, 3000, 625, 900, 5625, 22500, 40000, 40000, 22500, 5625, 900, 1296, 9450, 50625, 105000, 160000, 105000, 50625, 9450
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..0..0..0..1....0..0..0..0..0....0..0..1..0..1....0..0..0..1..1 ..0..1..0..1..1....0..0..0..1..0....1..1..1..1..1....0..0..1..1..1 ..0..0..1..0..1....0..0..0..1..0....0..0..1..1..1....0..0..1..1..1 ..0..1..1..1..1....0..0..0..1..0....1..1..1..1..1....0..0..1..1..1 ..0..1..1..1..1....0..0..0..1..0....0..1..1..1..1....1..0..1..1..1 ..0..1..1..1..1....0..0..0..1..1....1..1..1..1..1....1..1..1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..1104
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) +2*a(n-2) -6*a(n-3) +6*a(n-5) -2*a(n-6) -2*a(n-7) +a(n-8); also a polynomial of degree 4 plus a quasipolynomial of degree 2 with period 2
k=2: [order 12; also a polynomial of degree 6 plus a quasipolynomial of degree 4 with period 2]
k=3: [order 16; also a polynomial of degree 8 plus a quasipolynomial of degree 6 with period 2]
k=4: [order 20; also a polynomial of degree 10 plus a quasipolynomial of degree 8 with period 2]
k=5: [order 24; also a polynomial of degree 12 plus a quasipolynomial of degree 10 with period 2]
k=6: [order 28; also a polynomial of degree 14 plus a quasipolynomial of degree 12 with period 2]
k=7: [order 32; also a polynomial of degree 16 plus a quasipolynomial of degree 14 with period 2]
Comments