A235675 Number of (n+1)X(4+1) 0..1 arrays with the difference between each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise.
742, 15790, 330840, 6894210, 143484144, 2985166430, 62100488254, 1291848133836, 26873571586520, 559034577488572, 11629252189546650, 241916151493365248, 5032432178704803216, 104686575579504167834, 2177730111458692702436
Offset: 1
Keywords
Examples
Some solutions for n=2 ..0..1..0..0..0....1..1..1..1..0....1..1..0..0..0....0..1..0..0..0 ..1..1..0..1..1....0..0..0..0..0....1..0..0..1..1....0..0..1..1..1 ..1..1..0..0..1....0..1..1..1..1....0..0..1..0..0....0..0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 25*a(n-1) -56*a(n-2) -760*a(n-3) +1870*a(n-4) +9093*a(n-5) -19671*a(n-6) -53908*a(n-7) +96797*a(n-8) +165297*a(n-9) -249510*a(n-10) -263103*a(n-11) +342224*a(n-12) +215121*a(n-13) -241863*a(n-14) -95529*a(n-15) +88208*a(n-16) +23290*a(n-17) -16128*a(n-18) -2854*a(n-19) +1362*a(n-20) +136*a(n-21) -40*a(n-22)
Comments