login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A318020 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
8, 35, 133, 569, 2227, 9063, 37030, 153117, 634563, 2638225, 10982346, 45752446, 190717173, 795215367, 3316427798, 13832535622, 57698440650, 240682257990, 1004002784204, 4188247714891, 17471641410509, 72884884003250 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A318024.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) -5*a(n-2) -43*a(n-3) +43*a(n-4) +80*a(n-5) -81*a(n-6) +389*a(n-7) -166*a(n-8) -1663*a(n-9) +73*a(n-10) +382*a(n-11) -1004*a(n-12) +8420*a(n-13) +7017*a(n-14) -4732*a(n-15) -2578*a(n-16) -13225*a(n-17) -39864*a(n-18) -12992*a(n-19) +17783*a(n-20) +22252*a(n-21) +68630*a(n-22) +66472*a(n-23) +38631*a(n-24) -11186*a(n-25) -59925*a(n-26) -74469*a(n-27) -118580*a(n-28) -92365*a(n-29) -52929*a(n-30) +71335*a(n-31) +62509*a(n-32) +51480*a(n-33) +109573*a(n-34) +66423*a(n-35) -5605*a(n-36) -21559*a(n-37) +22798*a(n-38) -67343*a(n-39) -60989*a(n-40) +24323*a(n-41) +1112*a(n-42) -37873*a(n-43) +24020*a(n-44) +38942*a(n-45) -22226*a(n-46) -5050*a(n-47) +18426*a(n-48) -1034*a(n-49) -17141*a(n-50) -3370*a(n-51) +11008*a(n-52) -3889*a(n-53) -7151*a(n-54) +4729*a(n-55) +4215*a(n-56) -2118*a(n-57) -1964*a(n-58) +3078*a(n-59) -463*a(n-60) -286*a(n-61) -1062*a(n-62) +1505*a(n-63) -828*a(n-64) -31*a(n-65) +196*a(n-66) -52*a(n-67) -33*a(n-68) +28*a(n-69) -4*a(n-70) for n>74

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A318024.

Sequence in context: A292479 A301881 A094616 * A114569 A189599 A302078

Adjacent sequences:  A318017 A318018 A318019 * A318021 A318022 A318023

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 12 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 8 08:44 EDT 2020. Contains 333313 sequences. (Running on oeis4.)