A304415 Number of nX4 0..1 arrays with every element unequal to 0, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.

1, 24, 103, 835, 7017, 60245, 522349, 4542604, 39567170, 344867709, 3006637339, 26216229524, 228603730278, 1993460011680, 17383499694996, 151589509899903, 1321910981585320, 11527517181690855, 100523956632846546

Offset

1,2

Comments

Column 4 of A304419.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +18*a(n-2) -126*a(n-3) -642*a(n-4) +947*a(n-5) +5892*a(n-6) +3421*a(n-7) -22541*a(n-8) -42456*a(n-9) -1502*a(n-10) +84330*a(n-11) +92320*a(n-12) +84252*a(n-13) +179487*a(n-14) +61076*a(n-15) -686553*a(n-16) -1365118*a(n-17) -335218*a(n-18) +1910366*a(n-19) +2465234*a(n-20) -56719*a(n-21) -2858935*a(n-22) -3505136*a(n-23) -1217142*a(n-24) +2480294*a(n-25) +4393672*a(n-26) +2089476*a(n-27) -2038851*a(n-28) -2486979*a(n-29) +312720*a(n-30) +1131502*a(n-31) +154965*a(n-32) +141350*a(n-33) +726963*a(n-34) +185495*a(n-35) -603585*a(n-36) -371131*a(n-37) +146974*a(n-38) +296513*a(n-39) +79957*a(n-40) -44532*a(n-41) -43568*a(n-42) -3508*a(n-43) +6980*a(n-44) +80*a(n-46) +128*a(n-47) for n>48

Example

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

Crossrefs

Cf. A304419.

Sequence in context: A269047 A182675 A100155 * A268804 A186932 A275506

Adjacent sequences: A304412 A304413 A304414 * A304416 A304417 A304418

Keyword

nonn

Author

R. H. Hardin, May 12 2018

Status

approved