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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.

A229315 Number of nX2 0..3 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1)X3 0..3 array without adjacent equal elements in the latter.

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%I A229315 #6 Jul 23 2025 05:40:06
%S A229315 14,154,1494,13968,129766,1203222,11146054,103236194,956057048,
%T A229315 8853833056,81991894696,759294338246,7031507356914,65115840648102,
%U A229315 603010344430850,5584224380804470,51713144710842856,478893600594242612
%N A229315 Number of nX2 0..3 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1)X3 0..3 array without adjacent equal elements in the latter.
%C A229315 Column 2 of A229320
%H A229315 R. H. Hardin, <a href="/A229315/b229315.txt">Table of n, a(n) for n = 1..176</a>
%F A229315 Empirical: a(n) = 12*a(n-1) -12*a(n-2) -170*a(n-3) +413*a(n-4) +360*a(n-5) -2500*a(n-6) +4761*a(n-7) -7424*a(n-8) +8095*a(n-9) +1067*a(n-10) -10948*a(n-11) +5811*a(n-12) -5685*a(n-13) -5667*a(n-14) +43767*a(n-15) -42200*a(n-16) +63250*a(n-17) -114786*a(n-18) +139663*a(n-19) -210040*a(n-20) +242074*a(n-21) +11485*a(n-22) -229841*a(n-23) +246874*a(n-24) -495364*a(n-25) +424756*a(n-26) -414970*a(n-27) +601244*a(n-28) -811641*a(n-29) +1009456*a(n-30) -1380235*a(n-31) +1228145*a(n-32) -674904*a(n-33) +313339*a(n-34) +511282*a(n-35) -710123*a(n-36) +664496*a(n-37) -457843*a(n-38) +191690*a(n-39) +55758*a(n-40) -66502*a(n-41) +150610*a(n-42) +1481*a(n-43) +19304*a(n-44) -48928*a(n-45) +40006*a(n-46) -47878*a(n-47) -42105*a(n-48) -11482*a(n-49) -12568*a(n-50) +16105*a(n-51) +103*a(n-52) +5809*a(n-53) -2122*a(n-54) +4423*a(n-55) +601*a(n-56) -1525*a(n-57) -384*a(n-58) -1331*a(n-59) -98*a(n-60) +157*a(n-61) +5*a(n-62) +86*a(n-63) +11*a(n-64) -2*a(n-65)
%e A229315 Some solutions for n=3
%e A229315 ..1..3....2..3....3..1....2..3....2..1....0..3....2..0....1..1....1..2....1..1
%e A229315 ..3..1....1..0....2..2....2..0....3..1....2..2....0..2....0..2....2..3....0..2
%e A229315 ..1..1....0..1....3..1....0..3....1..0....1..0....2..0....1..1....3..0....3..2
%K A229315 nonn
%O A229315 1,1
%A A229315 _R. H. Hardin_ Sep 19 2013