A295648 Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 3 or 4 1s.

13, 106, 956, 8391, 74335, 657178, 5812860, 51408810, 454678898, 4021307228, 35565664275, 314553293487, 2782003528545, 24604870438879, 217612830093347, 1924632917243403, 17022028855667816, 150547911558922843

Offset

1,1

Comments

Column 4 of A295652.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -2*a(n-2) -70*a(n-3) -15*a(n-4) -184*a(n-5) +706*a(n-6) +2106*a(n-7) -792*a(n-8) -6280*a(n-9) -5372*a(n-10) +16188*a(n-11) -3933*a(n-12) -36012*a(n-13) +35886*a(n-14) +28798*a(n-15) -36841*a(n-16) +12395*a(n-17) +25955*a(n-18) -19428*a(n-19) -2514*a(n-20) +6957*a(n-21) +13470*a(n-22) -32992*a(n-23) +24518*a(n-24) -1429*a(n-25) +8121*a(n-26) -9435*a(n-27) +7706*a(n-28) -9608*a(n-29) -2622*a(n-30) -5376*a(n-31) +3063*a(n-32) -5596*a(n-33) +1043*a(n-34) -430*a(n-35) +128*a(n-36) +1310*a(n-37) +234*a(n-38) +430*a(n-39) +151*a(n-40) +66*a(n-41) +25*a(n-42) +5*a(n-43) -2*a(n-44) -a(n-45)

Example

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

Crossrefs

Cf. A295652.

Sequence in context: A155636 A055902 A295249 * A218093 A132261 A142364

Adjacent sequences: A295645 A295646 A295647 * A295649 A295650 A295651

Keyword

nonn

Author

R. H. Hardin, Nov 25 2017

Status

approved