A202331 Number of (n+1) X 5 binary arrays with consecutive windows of two bits considered as a binary number nondecreasing in every row and column.
49, 129, 289, 576, 1052, 1796, 2906, 4501, 6723, 9739, 13743, 18958, 25638, 34070, 44576, 57515, 73285, 92325, 115117, 142188, 174112, 211512, 255062, 305489, 363575, 430159, 506139, 592474, 690186, 800362, 924156, 1062791, 1217561
Offset: 1
Keywords
Examples
Some solutions for n=5: ..0..0..0..0..0....0..0..0..0..0....0..0..0..1..0....0..0..0..0..0 ..0..0..0..1..0....0..0..0..0..0....0..0..0..1..0....0..0..0..0..0 ..0..0..0..1..0....0..0..0..0..0....0..0..0..1..1....0..0..0..1..0 ..0..0..0..1..0....0..0..0..1..1....0..0..0..1..1....0..0..1..1..1 ..0..1..1..1..1....0..0..0..1..1....1..1..1..1..1....1..1..1..1..1 ..0..0..0..1..1....0..0..1..1..1....0..0..1..1..1....1..1..1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A202335.
Formula
Empirical: a(n) = (1/60)*n^5 + (3/8)*n^4 + 3*n^3 + (89/8)*n^2 + (1169/60)*n + 15.
Conjectures from Colin Barker, May 27 2018: (Start)
G.f.: x*(49 - 165*x + 250*x^2 - 203*x^3 + 86*x^4 - 15*x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
Comments