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A302151 Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
4, 1, 4, 5, 11, 34, 88, 271, 798, 2368, 7071, 21110, 63163, 188980, 565622, 1693239, 5069374, 15178832, 45451143, 136102762, 407567006, 1220499079, 3654940301, 10945255479, 32777313021, 98157159720, 293948595170, 880280943171 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A302150.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) -4*a(n-2) +6*a(n-3) -10*a(n-4) +11*a(n-5) -24*a(n-6) +11*a(n-7) -45*a(n-8) +22*a(n-9) -38*a(n-10) +39*a(n-11) -21*a(n-12) +68*a(n-13) +28*a(n-14) +73*a(n-15) -25*a(n-16) -16*a(n-17) -37*a(n-18) -11*a(n-19) -11*a(n-20) -16*a(n-21) -7*a(n-22) +3*a(n-24) +a(n-25) for n>27

EXAMPLE

Some solutions for n=5

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

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

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

CROSSREFS

Cf. A302150.

Sequence in context: A286327 A081773 A324836 * A167431 A205848 A297701

Adjacent sequences:  A302148 A302149 A302150 * A302152 A302153 A302154

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 02 2018

STATUS

approved

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Last modified December 8 05:35 EST 2021. Contains 349590 sequences. (Running on oeis4.)