A290043 - OEIS

%I #10 Aug 21 2017 09:50:44

%S 2,3,5,17,19,23,7433,7451,7457,7459,3080515841187937,3080515841187947,

%T 3080515841187989,3080515841188039,3080515841188057

%N Prime factors of A290042.

%F Product_{k=n(n-1)/2 + 1..n(n+1)/2} a(k) = A290042(n) for n > 0.

%e A290042(2) = 15 = 3*5, so 3 and 5 are members.

%Y Cf. A290042.

%K nonn

%O 1,1

%A _Jonathan Sondow_, Aug 20 2017