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.

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

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 A364148 A142650

Adjacent sequences: A302278 A302279 A302280 * A302282 A302283 A302284

Keyword

nonn

Author

R. H. Hardin, Apr 04 2018

Status

approved