A374796 - OEIS

%I #9 Jul 20 2024 15:07:51

%S 1,15,4095,66066

%N Positive integers that can be written as a Stirling number of the second kind in more than one way.

%C k*(k+1)/2 is a term if k is a term of A215797 and k != 0,2.

%C a(5) > 10^8 (if it exists).

%e With S2(n,k) = A008277(n,k):

%e       1 = S2( 1, 1) = S2(  2,  1) (for example);

%e      15 = S2( 5, 2) = S2(  6,  5);

%e    4095 = S2(13, 2) = S2( 91, 90);

%e   66066 = S2(14,11) = S2(364,363).

%Y Cf. A008277, A024412, A215797.

%K nonn,more

%O 1,2

%A _Pontus von Brömssen_, Jul 20 2024