cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A278184 Number of nX3 0..3 arrays with every element plus 1 mod 4 equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.

Original entry on oeis.org

0, 19, 544, 13720, 347116, 8803344, 223230876, 5660949042, 143557203008, 3640498372990, 92320193797850, 2341167983288042, 59370190792031534, 1505581649925192516, 38180374263992817136, 968224459304580152320
Offset: 1

Views

Author

R. H. Hardin, Nov 14 2016

Keywords

Comments

Column 3 of A278188.

Examples

			Some solutions for n=4
..0..2..3. .0..1..0. .0..3..2. .0..1..3. .0..3..2. .0..3..2. .0..2..1
..1..3..0. .0..2..3. .1..0..2. .3..2..0. .1..3..1. .1..2..1. .1..3..2
..2..0..1. .3..2..3. .2..0..2. .2..1..0. .2..1..0. .0..2..1. .0..3..1
..1..3..2. .2..1..0. .3..2..3. .0..1..3. .0..3..2. .3..3..2. .2..3..0
		

Crossrefs

Cf. A278188.

Formula

Empirical: a(n) = 31*a(n-1) -155*a(n-2) +301*a(n-3) +159*a(n-4) -2992*a(n-5) +9662*a(n-6) -29732*a(n-7) +126855*a(n-8) -280808*a(n-9) -58215*a(n-10) +1824424*a(n-11) -5134012*a(n-12) +7021960*a(n-13) -3782179*a(n-14) -161494*a(n-15) -12931*a(n-16) +1006187*a(n-17) +1090*a(n-18) -1012324*a(n-19) -2180228*a(n-20) +2329252*a(n-21) -1301360*a(n-22) +252136*a(n-23) +383856*a(n-24) +87584*a(n-25) -102976*a(n-26) +3840*a(n-27)