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A186916 Number of (n+1)X3 0..3 arrays with every 2X2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2X2 subblock traces 1
704, 13440, 253312, 4615296, 86388160, 1613838400, 30161413056, 563483938112, 10530498631296, 196771080244352, 3677047553720384, 68710487850849472, 1283968202554236992, 23992859339683816000, 448344090383733286912 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A186923

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n)=19*a(n-1)-42*a(n-2)+193*a(n-3)+11367*a(n-4)-72730*a(n-5)+643907*a(n-6)-2092699*a(n-7)+2358885*a(n-8)+3857288*a(n-9)-259965739*a(n-10)+923072651*a(n-11)-5781680009*a(n-12)+20491619898*a(n-13)+8894970587*a(n-14)-170675786175*a(n-15)+2368472286552*a(n-16)-8224292736101*a(n-17)+19330903243739*a(n-18)-105830953991576*a(n-19)+57206563938348*a(n-20)+891386946727050*a(n-21)-5108640876870042*a(n-22)+24293633672312964*a(n-23)-55854110178877757*a(n-24)+119328786504692099*a(n-25)-194223424712175754*a(n-26)-758065151423762303*a(n-27)+4705172061925685671*a(n-28)-19283863911879897678*a(n-29)+58477064112798375671*a(n-30)-115420288738501952295*a(n-31)+226881171676804374579*a(n-32)-227406016994050647282*a(n-33)-758918990518733400415*a(n-34)+3927514331879039801141*a(n-35)-14160407221007454217745*a(n-36)+38834128880307712389668*a(n-37)-84378310829784482421755*a(n-38)+186777993653737777355805*a(n-39)-342410464818158459976594*a(n-40)+482753241710170393509689*a(n-41)-694821224047356382119197*a(n-42)+701237606664586708235446*a(n-43)-75636310836208438477376*a(n-44)-941705253640376665897824*a(n-45)+4194854884439913213614720*a(n-46)-9313648502362966805603808*a(n-47)+12537306334386180437424128*a(n-48)-22495404254986469017386624*a(n-49)+34226776839938528858360064*a(n-50)-24704967584148780932904448*a(n-51)+21360185887183265068596224*a(n-52)-23926309520806603554521088*a(n-53)-30199236051497551149019136*a(n-54)+90054299370892913001701376*a(n-55)-121240337983554757193908224*a(n-56)+207295579318514130921553920*a(n-57)-294027413230123317961555968*a(n-58)+327991241277559585551679488*a(n-59)-369179644394232254698094592*a(n-60)+371716373430578247204077568*a(n-61)-333020475532786703168176128*a(n-62)+302328724884170573460013056*a(n-63)-227155277320893889561755648*a(n-64)+139239457898080848662495232*a(n-65)-97256446345939717088870400*a(n-66)+56212147213798847608258560*a(n-67)-13897379972622097317888000*a(n-68)

EXAMPLE

Some solutions for 5X3

..0..0..0....0..2..0....2..2..0....2..0..0....0..0..0....2..2..0....0..0..0

..1..0..0....1..2..0....1..2..2....1..0..2....3..0..0....3..2..2....3..2..2

..0..0..1....0..1..0....3..1..0....2..3..2....0..0..1....1..1..0....2..1..2

..1..1..1....1..1..3....3..2..1....1..2..1....1..3..1....2..3..1....1..1..0

..1..3..3....1..0..3....3..2..3....1..2..1....1..2..0....3..3..2....0..2..0

CROSSREFS

Sequence in context: A237009 A185568 A185799 * A185800 A188368 A185569

Adjacent sequences:  A186913 A186914 A186915 * A186917 A186918 A186919

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 28 2011 28 2011

STATUS

approved

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Last modified December 6 19:15 EST 2021. Contains 349567 sequences. (Running on oeis4.)