A373514 - OEIS

%I #10 Jul 20 2024 18:06:18

%S 0,1,1,0,2,1,1,1,4,3,1,6,3,8,2,3,9,6,2,8,14,10,14,4,14,20,10,2,14,24,

%T 15,18,6,27,30,19,34,21,26,22,33,10,13,30,5,44,38,30,41,26,36,25,56,

%U 17,58,52,38,51,40,63,45,41,46,76,47,70,72,55,15,80,6

%N Number of simple difference sets of the Singer type (m^2 + m + 1, m + 1, 1) that are a superset of {0, 1, 3} with m = m(n) = A000961(n), for n >= 1.

%H Martin Becker, <a href="/A373514/b373514.txt">Table of n, a(n) for n = 1..400</a>

%e For n=5, m=5, there are 2 Singer type planar difference sets of order 5 containing 0, 1, and 3: {0,1,3,8,12,18} and {0,1,3,10,14,26}. Thus a(5) = 2.

%e For n=11, m=16, there is only 1 such set: {0,1,3,7,15,31,63,90,116,127,136,181,194,204,233,238,255}. Thus a(11) = 1.

%Y Cf. A335866, A000961, A373946. Counts sets in A333852 with the property that 3 is also in the set.

%K nonn

%O 1,5

%A _Martin Becker_, Jun 07 2024