A302729 Number of 4Xn 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

0, 23, 83, 89, 287, 689, 1723, 4491, 10433, 28009, 73289, 182043, 464679, 1196593, 3100505, 7907085, 20156111, 51965647, 133805425, 342839837, 878417801, 2258261501, 5808644113, 14907781647, 38258830449, 98318643559, 252713316537

Offset

1,2

Comments

Row 4 of A302728.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -28*a(n-2) +30*a(n-3) +10*a(n-4) -58*a(n-5) +90*a(n-6) +194*a(n-7) -716*a(n-8) -504*a(n-9) +2880*a(n-10) -2439*a(n-11) -603*a(n-12) +5413*a(n-13) +2691*a(n-14) -25582*a(n-15) +7826*a(n-16) +32125*a(n-17) -38449*a(n-18) +15678*a(n-19) +76779*a(n-20) -41293*a(n-21) -157975*a(n-22) +126885*a(n-23) +54074*a(n-24) -261248*a(n-25) +255719*a(n-26) +176028*a(n-27) -491272*a(n-28) +149210*a(n-29) +871343*a(n-30) -316050*a(n-31) -951297*a(n-32) +205706*a(n-33) -538272*a(n-34) -773585*a(n-35) +2370802*a(n-36) +2752713*a(n-37) -2295559*a(n-38) -4674958*a(n-39) +600525*a(n-40) +5090198*a(n-41) +2088636*a(n-42) -3591982*a(n-43) -4408726*a(n-44) +210159*a(n-45) +3826253*a(n-46) +2513568*a(n-47) -1239355*a(n-48) -2734497*a(n-49) -905283*a(n-50) +1359121*a(n-51) +1605315*a(n-52) +212821*a(n-53) -799018*a(n-54) -633291*a(n-55) -31315*a(n-56) +217481*a(n-57) +109705*a(n-58) -14479*a(n-59) -22849*a(n-60) +2283*a(n-61) +10439*a(n-62) +1190*a(n-63) -3341*a(n-64) -1094*a(n-65) +1132*a(n-66) +248*a(n-67) -160*a(n-68) for n>69

Example

Some solutions for n=5
..0..1..0..1..1. .0..0..1..0..0. .0..1..0..1..0. .0..0..1..1..0
..1..0..0..1..1. .0..0..1..1..0. .1..0..0..0..1. .1..0..1..0..0
..0..1..1..0..1. .0..1..0..0..0. .0..1..1..1..0. .0..1..1..0..1
..1..0..1..0..0. .1..1..0..1..1. .1..0..1..0..1. .0..0..1..1..1

Crossrefs

Cf. A302728.

Sequence in context: A160297 A210706 A304592 * A139940 A052073 A213174

Adjacent sequences: A302726 A302727 A302728 * A302730 A302731 A302732

Keyword

nonn

Author

R. H. Hardin, Apr 12 2018

Status

approved