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%I #4 Mar 02 2016 11:28:57
%S 7,49,343,2395,16681,115902,803434,5556909,38350583,264117327,
%T 1815254345,12451509292,85246693192,582545874403,3973788262533,
%U 27059842131395,183956317982661,1248518868323747,8460336000063413,57241697970038501
%N Number of length-n 0..6 arrays with no adjacent pair x,x+1 repeated.
%C Column 6 of A269656.
%H R. H. Hardin, <a href="/A269654/b269654.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 49*a(n-1) -1071*a(n-2) +13804*a(n-3) -117159*a(n-4) +695709*a(n-5) -3021382*a(n-6) +10023853*a(n-7) -26667942*a(n-8) +59661994*a(n-9) -116448220*a(n-10) +203589267*a(n-11) -324797263*a(n-12) +479027591*a(n-13) -659300067*a(n-14) +852873532*a(n-15) -1042800234*a(n-16) +1210501656*a(n-17) -1338796662*a(n-18) +1414739998*a(n-19) -1431668679*a(n-20) +1390012356*a(n-21) -1296744764*a(n-22) +1163755845*a(n-23) -1005616962*a(n-24) +837248601*a(n-25) -671927508*a(n-26) +519927877*a(n-27) -387912963*a(n-28) +279014001*a(n-29) -193401978*a(n-30) +129119305*a(n-31) -82960080*a(n-32) +51242821*a(n-33) -30387210*a(n-34) +17270445*a(n-35) -9387672*a(n-36) +4867688*a(n-37) -2399859*a(n-38) +1120399*a(n-39) -492772*a(n-40) +202839*a(n-41) -77471*a(n-42) +27132*a(n-43) -8568*a(n-44) +2380*a(n-45) -560*a(n-46) +105*a(n-47) -14*a(n-48) +a(n-49)
%e Some solutions for n=6
%e ..5. .1. .1. .0. .3. .3. .2. .4. .4. .1. .5. .2. .0. .3. .4. .3
%e ..4. .0. .1. .1. .5. .3. .5. .2. .2. .1. .3. .3. .1. .5. .3. .3
%e ..2. .0. .2. .3. .1. .2. .1. .2. .2. .4. .0. .6. .6. .3. .1. .6
%e ..5. .0. .2. .1. .5. .0. .1. .3. .1. .2. .4. .0. .3. .3. .3. .1
%e ..3. .0. .2. .5. .4. .3. .1. .6. .2. .0. .0. .3. .0. .2. .0. .1
%e ..5. .6. .2. .4. .0. .2. .1. .4. .4. .1. .2. .4. .4. .1. .6. .1
%Y Cf. A269656.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 02 2016
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