A392963 - OEIS

%I #7 Feb 02 2026 16:23:45

%S 1,1,1,3,1,3,1,3,10,1,3,7,1,3,7,35,1,3,7,26,1,3,6,15,126,1,3,5,15,66,

%T 1,3,4,12

%N Irregular triangle read by rows: T(n,k) is the domination number of the Kneser graph K(n,k), 1 <= k <= n/2.

%H Patric R. J. Östergård, Zehui Shao, and Xiaodong Xu, <a href="https://doi.org/10.26493/1855-3974.491.b02">Bounds on the domination number of Kneser graphs</a>, Ars Mathematica Contemporanea, 9(2):197-205, 2015.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/KneserGraph.html">Kneser Graph</a>.

%e Triangle T(n,k) begins:

%e   n\k  1   2   3   4   5   6

%e   2    1

%e   3    1

%e   4    1   3

%e   5    1   3

%e   6    1   3   10

%e   7    1   3   7

%e   8    1   3   7   35

%e   9    1   3   7   26

%e  10    1   3   6   15  126

%e  11    1   3   5   15  66

%e  12    1   3   4   12  ?   462

%Y Cf. A354568.

%K nonn,tabf,more

%O 2,4

%A _Martin Fuller_, Jan 28 2026