A188841 Number of n X 7 binary arrays without the pattern 0 1 diagonally or vertically.
128, 987, 3280, 7753, 15504, 28101, 47652, 76912, 119416, 179630, 263120, 376740, 528840, 729495, 990756, 1326924, 1754848, 2294248, 2968064, 3802832, 4829088, 6081801, 7600836, 9431448, 11624808, 14238562, 17337424, 20993804, 25288472
Offset: 1
Keywords
Examples
Some solutions for 3 X 7: ..1..1..0..0..1..1..1....1..1..1..1..1..1..1....1..0..0..1..1..0..0 ..1..1..0..0..0..1..1....1..1..0..1..1..1..1....1..0..0..0..1..0..0 ..1..1..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..200
Crossrefs
Cf. A188843.
Formula
Empirical: a(n) = (1/5040)*n^7 + (1/72)*n^6 + (143/360)*n^5 + (53/9)*n^4 + (33667/720)*n^3 + (12679/72)*n^2 + (9439/70)*n - 572 for n>4.
Empirical g.f.: x*(128 - 37*x - 1032*x^2 + 1981*x^3 - 992*x^4 - 605*x^5 + 700*x^6 - 58*x^7 - 96*x^8 + 3*x^9 + 8*x^10 + x^11) / (1 - x)^8. - Colin Barker, May 01 2018
Comments