A201501 Number of n X 5 0..1 arrays with every row and column running average nondecreasing rightwards and downwards, and the number of instances of each value within one of each other.
2, 3, 12, 12, 40, 32, 98, 73, 204, 141, 380, 252, 650, 414, 1042, 649, 1590, 967, 2330, 1394, 3302, 1944, 4550, 2649, 6122, 3523, 8070, 4604, 10450, 5910, 13320, 7483, 16744, 9343, 20790, 11538, 25528, 14090, 31032, 17053, 37382, 20451, 44660, 24342
Offset: 1
Keywords
Examples
Some solutions for n=4: ..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..1..1 ..0..0..1..1..1....0..0..0..1..1....0..0..0..1..1....0..0..0..1..1 ..0..0..1..1..1....0..1..1..1..1....0..0..1..1..1....0..0..1..1..1 ..0..1..1..1..1....0..1..1..1..1....1..1..1..1..1....0..0..1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A201503.
Formula
Empirical: a(n) = a(n-1) +2*a(n-2) -3*a(n-3) +a(n-4) +2*a(n-5) -4*a(n-6) +2*a(n-7) +2*a(n-8) -4*a(n-9) +4*a(n-11) -2*a(n-12) -2*a(n-13) +4*a(n-14) -2*a(n-15) -a(n-16) +3*a(n-17) -2*a(n-18) -a(n-19) +a(n-20).
Even terms are A188183((n-2)/2).
Empirical g.f.: x*(2 + x + 5*x^2 + 11*x^4 - 3*x^5 + 12*x^6 + 3*x^7 + 5*x^8 - x^9 + 12*x^10 - 3*x^11 - x^12 + 5*x^13 - 2*x^14 - x^15 + 3*x^16 - 2*x^17 - x^18 + x^19) / ((1 - x)^5*(1 + x)^5*(1 - x + x^2)*(1 + x^2)^2*(1 + x^4)). - Colin Barker, May 23 2018
Comments