A269217 Number of 4Xn 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three exactly once.

0, 11424, 361728, 12548544, 394072704, 11985002256, 354189986208, 10261769266944, 292749231337728, 8250573640526208, 230241360762467712, 6372885696329678304, 175188945893347242144, 4787785430572600575216

Offset

1,2

Comments

Row 4 of A269214.

Links

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

Formula

Empirical: a(n) = 48*a(n-1) -424*a(n-2) -5664*a(n-3) +40624*a(n-4) +218356*a(n-5) -1300662*a(n-6) -2980700*a(n-7) +17916384*a(n-8) +2629424*a(n-9) -96328452*a(n-10) +132185980*a(n-11) -10936481*a(n-12) -91456900*a(n-13) +51588388*a(n-14) +9975760*a(n-15) -14279120*a(n-16) +2348160*a(n-17) +465152*a(n-18) -79872*a(n-19) -9216*a(n-20)

Example

Some solutions for n=2
..3..1. .3..2. .2..2. .2..0. .1..3. .3..1. .3..1. .1..3. .3..3. .2..0
..0..1. .2..1. .3..2. .1..3. .3..1. .1..3. .0..2. .2..3. .1..1. .0..0
..1..3. .0..0. .0..0. .2..3. .0..3. .2..3. .1..1. .1..1. .3..1. .1..1
..3..1. .1..1. .0..2. .0..0. .3..2. .3..1. .1..0. .1..1. .2..2. .0..2

Crossrefs

Cf. A269214.

Sequence in context: A262399 A115753 A257172 * A154064 A140922 A216363

Adjacent sequences: A269214 A269215 A269216 * A269218 A269219 A269220

Keyword

nonn

Author

R. H. Hardin, Feb 20 2016

Status

approved