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A059680 Triangle T(n,k) read by rows giving number of fixed 4 X k polyominoes with n cells (n >= 4, 1<=k<=n-3).

%I A059680 #10 Oct 02 2017 21:26:48
%S A059680 1,0,12,0,18,50,0,8,154,120,0,1,212,584,230,0,0,158,1396,1526,388,0,0,
%T A059680 62,2038,5154,3276,602,0,0,12,1952,11328,14192,6194,880,0,0,1,1232,
%U A059680 17598,41196,32824,10704,1230,0,0,0,488,19912,87980,117616,67284,17294,1660
%N A059680 Triangle T(n,k) read by rows giving number of fixed 4 X k polyominoes with n cells (n >= 4, 1<=k<=n-3).
%H A059680 Andrew Howroyd, <a href="/A059680/b059680.txt">Table of n, a(n) for n = 4..1278</a>
%H A059680 R. C. Read, <a href="http://cms.math.ca/cjm/v14/cjm1962v14.0001-0020.pdf">Contributions to the cell growth problem</a>, Canad. J. Math., 14 (1962), 1-20.
%F A059680 T(n,k) = 0 for n > 4*k. - _Andrew Howroyd_, Oct 02 2017
%e A059680 Triangle starts:
%e A059680 1;
%e A059680 0, 12;
%e A059680 0, 18,  50;
%e A059680 0,  8, 154,  120;
%e A059680 0,  1, 212,  584,   230;
%e A059680 0,  0, 158, 1396,  1526,   388;
%e A059680 0,  0,  62, 2038,  5154,  3276,  602;
%e A059680 0,  0,  12, 1952, 11328, 14192, 6194, 880;
%e A059680 ...
%Y A059680 Column sums are A034187.
%Y A059680 Cf. A059678, A059679, A059681, A059684.
%K A059680 nonn,easy,nice,tabl
%O A059680 4,3
%A A059680 _N. J. A. Sloane_, Feb 05 2001
%E A059680 Terms a(32) and beyond from _Andrew Howroyd_, Oct 02 2017