A202199 Number of (n+2) X 7 binary arrays avoiding patterns 001 and 101 in rows and columns.
1176, 4704, 14700, 38808, 90552, 192192, 378378, 700700, 1233232, 2079168, 3378648, 5317872, 8139600, 12155136, 17757894, 25438644, 35802536, 49588000, 67687620, 91171080, 121310280, 159606720, 207821250, 268006284, 342540576
Offset: 1
Keywords
Examples
Some solutions for n=2: ..1..1..1..1..1..1..0....1..1..1..0..0..0..0....0..1..1..1..1..1..1 ..1..1..1..1..1..0..0....1..1..1..1..1..1..1....1..1..1..1..1..0..0 ..1..0..0..0..0..0..0....1..0..0..0..0..0..0....1..1..1..1..0..0..0 ..1..0..0..0..0..0..0....0..0..0..0..0..0..0....1..0..0..0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A202202.
Formula
Empirical: a(n) = 7*(n+7)*(n+6)*(n+5)*(n+4)*(n+3)*(n+2)^2/360.
Conjectures from Colin Barker, May 27 2018: (Start)
G.f.: 14*x*(84 - 336*x + 714*x^2 - 924*x^3 + 756*x^4 - 384*x^5 + 111*x^6 - 14*x^7) / (1 - x)^8.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.
(End)
Comments