A240480 - OEIS

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A240480

Number of nX4 0..1 arrays with no element equal to more than two horizontal or vertical neighbors, with new values 0..1 introduced in row major order

8, 81, 578, 4104, 29084, 205754, 1455916, 10304849, 72937769, 516249590, 3653997013, 25862854244, 183056241833, 1295664762145, 9170663523390, 64909590438320, 459427491120642, 3251809452014192, 23016177558642426

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 4 of A240484

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) +2*a(n-2) -7*a(n-3) -25*a(n-4) -6*a(n-5) +150*a(n-6) +12*a(n-7) -456*a(n-8) -134*a(n-9) +408*a(n-10) +116*a(n-11) -171*a(n-12) +73*a(n-13) +388*a(n-14) +87*a(n-15) -127*a(n-16) -168*a(n-17) -62*a(n-18) -12*a(n-19) +16*a(n-20) +8*a(n-21) +2*a(n-22)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A027768 A236749 A343274 * A274752 A240632 A007792

Adjacent sequences: A240477 A240478 A240479 * A240481 A240482 A240483

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 06 2014

STATUS

approved