A295093 Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 3 1s.

4, 24, 114, 578, 2859, 14187, 70982, 353880, 1763742, 8792075, 43834726, 218552639, 1089593715, 5432145667, 27082226021, 135020029240, 673148618666, 3356010198589, 16731535456995, 83415827627182, 415873350543689

Offset

1,1

Comments

Column 4 of A295097.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +2*a(n-2) +12*a(n-3) +24*a(n-4) -12*a(n-5) -192*a(n-6) -183*a(n-7) +99*a(n-8) +13*a(n-9) +377*a(n-10) +690*a(n-11) -19*a(n-12) +305*a(n-13) +358*a(n-14) -841*a(n-15) +269*a(n-16) -2630*a(n-17) -190*a(n-18) -818*a(n-19) -1094*a(n-20) +2834*a(n-21) -1033*a(n-22) +1681*a(n-23) +597*a(n-24) +96*a(n-25) +1650*a(n-26) -332*a(n-27) +101*a(n-28) +59*a(n-29) -804*a(n-30) -338*a(n-31) -291*a(n-32) -285*a(n-33) +50*a(n-34) +18*a(n-35) +29*a(n-36) +26*a(n-37) -30*a(n-38) -20*a(n-39) -10*a(n-40) -5*a(n-41) +9*a(n-42) +7*a(n-43) -a(n-44) -a(n-45)

Example

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

Crossrefs

Cf. A295097.

Sequence in context: A272253 A300581 A099582 * A211142 A374389 A272735

Adjacent sequences: A295090 A295091 A295092 * A295094 A295095 A295096

Keyword

nonn

Author

R. H. Hardin, Nov 14 2017

Status

approved