111928domain: NAppears in sequencesNumbers k such that sigma(k+2) = 2*sigma(k-2).at n=6A067135Number of n X 4 1..2 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in nondecreasing order.at n=37A166805