A297854 Number of nX4 0..1 arrays with every element equal to 1, 2 or 4 king-move adjacent elements, with upper left element zero.
2, 13, 19, 30, 53, 90, 145, 244, 406, 771, 1396, 2472, 4358, 7688, 13953, 25626, 46458, 83576, 150333, 271566, 494639, 900920, 1633015, 2955455, 5353266, 9717165, 17670119, 32099391, 58228907, 105619960, 191684445, 348131289, 632389497
Offset: 1
Keywords
Examples
Some solutions for n=7 ..0..1..0..0. .0..1..1..0. .0..1..0..0. .0..0..1..1. .0..1..1..1 ..0..1..1..1. .0..1..0..0. .0..0..1..1. .1..0..1..0. .1..0..0..0 ..1..1..0..0. .0..1..1..1. .1..1..0..1. .0..1..0..1. .1..0..0..1 ..0..0..1..1. .1..1..0..0. .0..0..0..0. .1..1..0..0. .0..1..1..1 ..1..0..0..0. .0..0..1..1. .1..0..1..1. .1..1..0..0. .1..1..0..0 ..1..0..1..1. .1..1..1..0. .1..1..0..0. .0..1..0..1. .0..0..1..1 ..1..0..0..1. .0..0..1..0. .0..0..1..0. .0..0..0..1. .0..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A297858.
Formula
Empirical: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -2*a(n-4) +2*a(n-5) +a(n-6) -22*a(n-7) +22*a(n-9) +16*a(n-10) +14*a(n-11) +10*a(n-12) -4*a(n-13) -40*a(n-14) -26*a(n-15) -24*a(n-16) -12*a(n-17) -9*a(n-18) +33*a(n-19) +55*a(n-20) +13*a(n-21) +6*a(n-22) +10*a(n-23) +31*a(n-24) -24*a(n-25) -29*a(n-26) -4*a(n-27) -31*a(n-28) -25*a(n-29) +6*a(n-30) +22*a(n-31) +10*a(n-32) for n>37
Comments