A280359 Number of nX4 0..2 arrays with no element equal to more than one of its horizontal and vertical neighbors and with new values introduced in order 0 sequentially upwards.

11, 285, 6727, 164326, 3992071, 97147710, 2363431872, 57503068637, 1399048151083, 34038954765446, 828169917765970, 20149430911202735, 490237018170118357, 11927499978469804063, 290196884767995060095

Offset

1,1

Comments

Column 4 of A280362.

Links

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

Formula

Empirical: a(n) = 30*a(n-1) -103*a(n-2) -1092*a(n-3) +5847*a(n-4) +2804*a(n-5) -50379*a(n-6) +41079*a(n-7) -126386*a(n-8) +1514584*a(n-9) -1194277*a(n-10) -6905803*a(n-11) +6655712*a(n-12) +16213430*a(n-13) -21948067*a(n-14) -16861080*a(n-15) +41679338*a(n-16) +426137*a(n-17) -57615511*a(n-18) +28148770*a(n-19) +60186728*a(n-20) -41569682*a(n-21) -23465826*a(n-22) +95973316*a(n-23) -9699443*a(n-24) -206500242*a(n-25) -85311247*a(n-26) +112347612*a(n-27) +89204829*a(n-28) +124190867*a(n-29) +185283712*a(n-30) -74437936*a(n-31) -288002168*a(n-32) -164637824*a(n-33) +109790912*a(n-34) +171661568*a(n-35) +34990720*a(n-36) -45687040*a(n-37) -38017024*a(n-38) -10430464*a(n-39) +9265152*a(n-40) +5439488*a(n-41) +950272*a(n-42) -262144*a(n-43) -524288*a(n-44)

Example

Some solutions for n=4
..0..1..0..2. .0..1..0..1. .0..1..0..0. .0..0..1..0. .0..1..2..1
..1..0..1..1. .0..2..1..0. .1..0..2..2. .1..2..1..2. .0..2..1..0
..0..1..0..2. .1..1..0..1. .1..2..1..0. .0..1..2..1. .2..0..2..2
..2..1..2..1. .0..0..1..0. .2..1..2..0. .1..2..0..2. .1..2..1..0

Crossrefs

Cf. A280362.

Sequence in context: A274780 A323311 A355428 * A196790 A166182 A064758

Adjacent sequences: A280356 A280357 A280358 * A280360 A280361 A280362

Keyword

nonn

Author

R. H. Hardin, Jan 01 2017

Status

approved