%I #6 Jun 12 2019 13:56:52

%S 60,336,261888,229909120,738152448,25500590080

%N 1/2 times 3-perfect (triply perfect, tri-perfect, triperfect or sous-double) numbers: a(n) = A005820(n)/2.

%C If any odd perfect numbers exist, they should occur in this sequence, unless it is already complete, as some people believe. Please see comments and links in A005820.

%H <a href="/index/O#opnseqs">Index entries for sequences where any odd perfect numbers must occur</a>

%F a(n) = A005820(n)/2.

%Y Cf. A005820.

%K nonn,more,hard

%O 1,1

%A _Antti Karttunen_, Jun 12 2019