A304259 Number of nX4 0..1 arrays with every element unequal to 2, 3, 5 or 7 king-move adjacent elements, with upper left element zero.

0, 9, 13, 19, 47, 88, 181, 376, 878, 2001, 4424, 10341, 22952, 52556, 120613, 274291, 628125, 1438641, 3287013, 7536973, 17256538, 39516094, 90565077, 207484145, 475398131, 1089513951, 2496621606, 5721591782, 13112958593, 30051839551

Offset

1,2

Comments

Column 4 of A304263.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +2*a(n-3) -12*a(n-4) -17*a(n-5) -3*a(n-6) +4*a(n-7) +56*a(n-8) +57*a(n-9) +21*a(n-10) -82*a(n-11) -33*a(n-12) +212*a(n-13) +21*a(n-14) -461*a(n-15) -644*a(n-16) -41*a(n-17) +85*a(n-18) -1462*a(n-19) -738*a(n-20) +2418*a(n-21) +5962*a(n-22) +4902*a(n-23) -2142*a(n-24) -5883*a(n-25) -7569*a(n-26) +5615*a(n-27) +13037*a(n-28) +3919*a(n-29) -16383*a(n-30) -23961*a(n-31) +2853*a(n-32) +6808*a(n-33) -4059*a(n-34) -3044*a(n-35) +5350*a(n-36) -748*a(n-37) -17331*a(n-38) -32372*a(n-39) -2046*a(n-40) +33588*a(n-41) +32804*a(n-42) +30991*a(n-43) +11225*a(n-44) +27*a(n-45) +9447*a(n-46) +6794*a(n-47) -24410*a(n-48) -19890*a(n-49) +14509*a(n-50) +740*a(n-51) -22246*a(n-52) -4509*a(n-53) +9407*a(n-54) -3838*a(n-55) -2960*a(n-56) +3893*a(n-57) +1921*a(n-58) -502*a(n-59) +424*a(n-60) +314*a(n-61) -60*a(n-62) -28*a(n-63) for n>64

Example

Some solutions for n=5
..0..1..1..0. .0..1..1..0. .0..1..1..0. .0..0..0..1. .0..1..1..0
..1..0..1..1. .1..1..0..1. .1..0..0..1. .1..1..1..0. .0..1..1..0
..0..1..0..1. .1..0..1..0. .0..1..1..0. .1..0..0..1. .0..1..1..0
..0..0..1..0. .0..0..1..0. .1..0..0..1. .0..1..0..1. .0..0..0..0
..1..0..0..1. .1..1..0..1. .0..1..1..0. .0..1..1..0. .1..1..1..1

Crossrefs

Cf. A304263.

Sequence in context: A026283 A307287 A026045 * A124249 A137168 A033870

Adjacent sequences: A304256 A304257 A304258 * A304260 A304261 A304262

Keyword

nonn

Author

R. H. Hardin, May 09 2018

Status

approved