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Triangle T(n,k) read by rows: the number of n-node connected graphs with k components with no cycles of length less than 5.
1

%I #29 Mar 12 2018 07:38:31

%S 1,0,1,0,1,1,0,1,1,1,0,2,2,1,1,0,4,3,2,1,1,0,8,7,4,2,1,1,0,18,14,8,4,

%T 2,1,1,0,47,33,17,9,4,2,1,1,0,137,81,40,18,9,4,2,1,1,0,464,228,98,43,

%U 19,9,4,2,1,1,0,1793,716,269,105,44,19,9,4,2,1,1,0,8167,2596,827,287,108,45,19,9,4,2,1,1,0

%N Triangle T(n,k) read by rows: the number of n-node connected graphs with k components with no cycles of length less than 5.

%C Multiset transform of A126757.

%e The triangle starts in row n=0 with columns 0<=k<=n as:

%e 1;

%e 0 1

%e 0 1 1

%e 0 1 1 1

%e 0 2 2 1 1

%e 0 4 3 2 1 1

%e 0 8 7 4 2 1 1

%e 0 18 14 8 4 2 1 1

%e 0 47 33 17 9 4 2 1 1

%e 0 137 81 40 18 9 4 2 1 1

%e 0 464 228 98 43 19 9 4 2 1 1

%e 0 1793 716 269 105 44 19 9 4 2 1 1

%e 0 8167 2596 827 287 108 45 19 9 4 2 1 1

%e 0 43645 11030 2904 870 294 109 45 19 9 4 2 1 1

%e 0 275480 55628 11992 3022 888 297 110 45 19 9 4 2 1 1

%e 0 2045279 334676 58968 12320 3066 895 298 110 45 19 9 4 2 1 1

%e 0 17772647 2395216 348166 59991 12440 3084 898 299 110 45 19 9 4 2 1 1

%Y Cf. A126757 (column k=1), A006787 (row sums)

%K nonn,tabl

%O 0,12

%A _R. J. Mathar_, Mar 12 2018