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A284077 Number of 3Xn 0..1 arrays with no 1 equal to more than three of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements. 1
0, 0, 15, 275, 3174, 31898, 300008, 2695374, 23315931, 196337438, 1619907608, 13142006271, 105144896153, 831492737200, 6510374422284, 50537297389064, 389357648148684, 2979896274369314, 22671924767160815, 171584668641301626 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Row 3 of A284075.

LINKS

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

FORMULA

Empirical: a(n) = 15*a(n-1) -60*a(n-2) +125*a(n-3) -1137*a(n-4) +2028*a(n-5) +539*a(n-6) +39918*a(n-7) +71109*a(n-8) +182402*a(n-9) +118347*a(n-10) -296751*a(n-11) -1143516*a(n-12) -2568462*a(n-13) -2234631*a(n-14) +771008*a(n-15) +7215516*a(n-16) +14200866*a(n-17) +12041819*a(n-18) -2280720*a(n-19) -23475099*a(n-20) -35927647*a(n-21) -23058894*a(n-22) +10637571*a(n-23) +37847467*a(n-24) +34806129*a(n-25) +8813067*a(n-26) -14068429*a(n-27) -18555168*a(n-28) -9925527*a(n-29) -713731*a(n-30) +3039399*a(n-31) +2593371*a(n-32) +1126644*a(n-33) +233214*a(n-34) -32427*a(n-35) -39237*a(n-36) -11907*a(n-37) -705*a(n-38) +613*a(n-39) +174*a(n-40) +12*a(n-41) -8*a(n-42)

EXAMPLE

Some solutions for n=4

..0..1..1..1. .1..0..0..0. .0..1..1..0. .1..0..1..1. .0..0..1..1

..1..1..0..1. .1..1..1..1. .1..1..1..1. .0..1..1..1. .1..1..1..1

..1..1..1..0. .1..1..1..0. .1..1..0..1. .1..1..1..0. .0..0..1..1

CROSSREFS

Cf. A284075.

Sequence in context: A195615 A156091 A194728 * A339118 A034687 A159239

Adjacent sequences:  A284074 A284075 A284076 * A284078 A284079 A284080

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 19 2017

STATUS

approved

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Last modified August 7 23:50 EDT 2022. Contains 355995 sequences. (Running on oeis4.)