A269204 Number of 4Xn 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three no more than once.

256, 15540, 471492, 15289548, 463790340, 13753913556, 399104835612, 11402099212308, 321701652077076, 8985658235129964, 248904744378939924, 6846738391062856596, 187219797100389992412, 5093241917191742737620

Offset

1,1

Comments

Row 4 of A269201.

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. .0..2. .1..1. .3..3. .3..1. .2..3. .3..2. .2..2. .0..3. .3..2
..3..2. .0..1. .1..3. .2..3. .1..1. .1..0. .3..1. .3..2. .2..0. .2..3
..3..3. .0..0. .3..1. .3..3. .1..1. .0..2. .1..3. .2..0. .1..3. .2..3
..1..2. .1..1. .3..3. .0..1. .2..3. .2..0. .1..1. .1..3. .2..0. .2..2

Crossrefs

Cf. A269201.

Sequence in context: A238073 A017032 A136286 * A224283 A224206 A238064

Adjacent sequences: A269201 A269202 A269203 * A269205 A269206 A269207

Keyword

nonn

Author

R. H. Hardin, Feb 20 2016

Status

approved