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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.

A298446 Triangle T(n,k) read by rows: number of n-node connected graphs with rectilinear crossing number k (k=0..A014540(n)).

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%I A298446 #27 Feb 16 2025 08:33:53
%S A298446 1,1,2,6,20,1,99,11,1,1,646,149,38,15,1,2,1,0,0,1,5974,3008,1251,542,
%T A298446 171,80,47,12,15,7,4,1,3,0,0,1,0,0,0,1,71885
%N A298446 Triangle T(n,k) read by rows: number of n-node connected graphs with rectilinear crossing number k (k=0..A014540(n)).
%C A298446 Computed up to n=8 using data provided by Geoffrey Exoo.  (There appear to be some problems with n=9 data.)
%C A298446 T(9,1) >= 71335. - _Eric W. Weisstein_, Mar 28 2019
%H A298446 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConnectedGraph.html">Connected Graph</a>
%H A298446 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RectilinearCrossingNumber.html">Rectilinear Crossing Number</a>
%F A298446 T(n,0) = A003094(n).
%F A298446 kmax(n) = A014540(n).
%F A298446 T(n,kmax(n)) = 1 for n > 4.
%F A298446 sum(k=0..kmax(n), T(n,k)) = A001349(n).
%e A298446 Triangle begins:
%e A298446 1
%e A298446 1
%e A298446 2
%e A298446 6
%e A298446 20,1
%e A298446 99,11,1,1
%e A298446 646,149,38,15,1,2,1,0,0,1
%e A298446 5974,3008,1251,542,171,80,47,12,15,7,4,1,3,0,0,1,0,0,0,1
%Y A298446 Cf. A014540 (rectilinear crossing number for K_n).
%Y A298446 Cf. A298445 (counts for simple graph).
%K A298446 nonn,tabf
%O A298446 1,3
%A A298446 _Eric W. Weisstein_, Jan 19 2018
%E A298446 Corrected by _Eric W. Weisstein_, Mar 28 2019