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A302281 Number of 4 X n 0..1 arrays with every element equal to 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1
0, 23, 79, 89, 283, 649, 1621, 4209, 9563, 25179, 64825, 159647, 400017, 1006221, 2575287, 6472771, 16199339, 41000497, 103869515, 262156417, 659973671, 1666508525, 4216930049, 10647519701, 26860910357, 67834767395, 171448094515 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A302278.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) -30*a(n-2) +46*a(n-3) -33*a(n-4) -19*a(n-5) +98*a(n-6) +116*a(n-7) -592*a(n-8) -10*a(n-9) +1664*a(n-10) -3336*a(n-11) +4033*a(n-12) -1166*a(n-13) +4404*a(n-14) -13735*a(n-15) +7376*a(n-16) +1355*a(n-17) -18717*a(n-18) +29639*a(n-19) +14401*a(n-20) +8775*a(n-21) -77658*a(n-22) +93150*a(n-23) -97491*a(n-24) -71212*a(n-25) +130345*a(n-26) +49353*a(n-27) -127543*a(n-28) +152511*a(n-29) +202885*a(n-30) -123547*a(n-31) -284655*a(n-32) -66410*a(n-33) -373017*a(n-34) -221791*a(n-35) +903034*a(n-36) +1323425*a(n-37) -122321*a(n-38) -1724187*a(n-39) -1155725*a(n-40) +507750*a(n-41) +1558721*a(n-42) +674800*a(n-43) -628203*a(n-44) -1015347*a(n-45) -246589*a(n-46) +496217*a(n-47) +496065*a(n-48) -14686*a(n-49) -252018*a(n-50) -141359*a(n-51) +56873*a(n-52) +84461*a(n-53) +12753*a(n-54) -29638*a(n-55) -11825*a(n-56) +7760*a(n-57) +6456*a(n-58) -3328*a(n-59) -3618*a(n-60) +308*a(n-61) +1056*a(n-62) +96*a(n-63) -128*a(n-64) for n>66.

EXAMPLE

Some solutions for n=5:

  0 1 0 1 0     0 0 1 1 1     0 0 1 0 0     0 1 0 1 0

  1 0 0 0 1     1 0 0 0 0     1 1 1 0 1     1 0 1 0 1

  1 1 0 1 1     1 1 1 0 1     1 0 0 1 1     1 0 1 0 1

  1 0 1 0 1     0 0 1 1 1     1 1 0 1 1     0 1 0 1 0

CROSSREFS

Cf. A302278.

Sequence in context: A157270 A102109 A238677 * A141974 A142650 A078597

Adjacent sequences:  A302278 A302279 A302280 * A302282 A302283 A302284

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 04 2018

STATUS

approved

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Last modified October 25 01:18 EDT 2020. Contains 338010 sequences. (Running on oeis4.)