A297872 Number of nX4 0..1 arrays with every element equal to 2, 3 or 5 king-move adjacent elements, with upper left element zero.
0, 2, 3, 10, 20, 68, 185, 561, 1588, 4814, 14322, 42658, 127606, 381695, 1142358, 3419569, 10243325, 30685488, 91937645, 275496007, 825602377, 2474298468, 7415685876, 22226227933, 66617647655, 199673303891, 598488700247
Offset: 1
Keywords
Examples
Some solutions for n=7 ..0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..1..1 ..1..0..1..0. .1..0..1..0. .0..1..0..1. .0..1..0..1. .0..1..1..0 ..1..1..0..0. .1..1..0..0. .0..1..0..1. .1..0..1..0. .1..0..0..0 ..1..0..1..0. .1..0..1..0. .1..0..0..1. .1..0..1..0. .1..0..1..0 ..0..0..1..1. .0..0..1..0. .0..1..0..1. .1..1..0..1. .0..1..1..0 ..1..0..1..0. .1..0..1..0. .0..1..0..1. .0..1..1..0. .1..0..1..0 ..1..1..0..0. .1..1..0..0. .0..0..1..1. .0..0..0..0. .1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A297876.
Formula
Empirical: a(n) = 5*a(n-1) -5*a(n-2) -2*a(n-3) -5*a(n-4) +3*a(n-5) +36*a(n-7) -57*a(n-8) +81*a(n-9) +32*a(n-10) -6*a(n-11) -102*a(n-12) -12*a(n-13) -182*a(n-14) -286*a(n-15) +443*a(n-16) -410*a(n-17) +222*a(n-18) -755*a(n-19) +2597*a(n-20) -997*a(n-21) +788*a(n-22) -95*a(n-23) +2600*a(n-24) -2288*a(n-25) -2866*a(n-26) -1124*a(n-27) +2189*a(n-28) -1950*a(n-29) -3437*a(n-30) +2422*a(n-31) +115*a(n-32) +1748*a(n-33) +1283*a(n-34) +1645*a(n-35) +38*a(n-36) +415*a(n-37) -862*a(n-38) +338*a(n-39) -437*a(n-40) -1030*a(n-41) -286*a(n-42) -150*a(n-43) +337*a(n-44) -83*a(n-45) +41*a(n-46) -33*a(n-47) +71*a(n-48) +14*a(n-49) +8*a(n-50) -6*a(n-51) -4*a(n-52) for n>53
Comments