cp's OEIS Frontend

A038195 Triangle read by rows: T(n,k) (n >= 2, 0 <= k <= n) = number of over-all crude totals of unbranched k-5-catapolyheptagons.

%I A038195 #20 Jul 08 2025 22:09:46
%S A038195 1,2,1,4,10,8,2,16,48,52,24,4,64,224,304,200,64,8,256,1024,1664,1408,
%T A038195 656,160,16,1024,4608,8704,8960,5440,1952,384,32,4096,20480,44032,
%U A038195 53248,39680,18688,5440,896,64,16384,90112,217088,301056,265216,154112,59136,14464,2048,128
%N A038195 Triangle read by rows: T(n,k) (n >= 2, 0 <= k <= n) = number of over-all crude totals of unbranched k-5-catapolyheptagons.
%D A038195 B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121. See Table 1.
%F A038195 T(n,k) = 2^(2*n-k-2)*(binomial(n-1,k-1)+binomial(n-2,k)/4).
%e A038195 Triangle begins:
%e A038195 [1, 2, 1],
%e A038195 [4, 10, 8, 2],
%e A038195 [16, 48, 52, 24, 4],
%e A038195 [64, 224, 304, 200, 64, 8],
%e A038195 [256, 1024, 1664, 1408, 656, 160, 16],
%e A038195 [1024, 4608, 8704, 8960, 5440, 1952, 384, 32],
%e A038195 [4096, 20480, 44032, 53248, 39680, 18688, 5440, 896, 64],
%e A038195 [16384, 90112, 217088, 301056, 265216, 154112, 59136, 14464, 2048, 128],
%e A038195 ...
%K A038195 nonn,tabf
%O A038195 2,2
%A A038195 _N. J. A. Sloane_
%E A038195 Revised by _N. J. A. Sloane_, Feb 08 2019