A281607 Number of 4Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

14, 285, 1623, 16198, 167545, 1626073, 15975093, 157271995, 1545421328, 15189232151, 149300998270, 1467524054601, 14424777071936, 141785299554627, 1393649553888429, 13698600339828853, 134647609111781265

Offset

1,1

Comments

Row 4 of A281605.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -15*a(n-2) +156*a(n-3) -380*a(n-4) +1391*a(n-5) -1460*a(n-6) +8345*a(n-7) -10168*a(n-8) -34575*a(n-9) +11685*a(n-10) +87520*a(n-11) -120741*a(n-12) -46402*a(n-13) +308504*a(n-14) -291257*a(n-15) -810689*a(n-16) +2625692*a(n-17) +2952825*a(n-18) -7688340*a(n-19) -5922696*a(n-20) +14554357*a(n-21) +5415000*a(n-22) -20140889*a(n-23) -1385535*a(n-24) +16904842*a(n-25) -5049800*a(n-26) -10379567*a(n-27) +5599204*a(n-28) +8253535*a(n-29) +1477700*a(n-30) -8713925*a(n-31) -5788589*a(n-32) +4890300*a(n-33) +7223068*a(n-34) +5210774*a(n-35) +2211358*a(n-36) -1353769*a(n-37) -3144958*a(n-38) -1967844*a(n-39) +184866*a(n-40) +874807*a(n-41) -332803*a(n-42) -12906*a(n-43) +212033*a(n-44) +14752*a(n-45) -77187*a(n-46) -21761*a(n-47) +8570*a(n-48) +10358*a(n-49) +283*a(n-50) -2122*a(n-51) -298*a(n-52) +252*a(n-53) +32*a(n-54) -8*a(n-55) for n>58

Example

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

Crossrefs

Cf. A281605.

Sequence in context: A291099 A053101 A205746 * A027401 A259432 A233069

Adjacent sequences: A281604 A281605 A281606 * A281608 A281609 A281610

Keyword

nonn

Author

R. H. Hardin, Jan 25 2017

Status

approved