Numbers that are the difference of two perfect numbers.
0, 22, 468, 490, 7632, 8100, 8122, 33542208, 33549840, 33550308, 33550330, 8556318720, 8589860928, 8589868560, 8589869028, 8589869050, 128848822272, 137405140992, 137438683200, 137438690832, 137438691300, 137438691322, 2305842870701260800
1
T. D. Noe, Plot of sorted differences of the first 15 perfect numbers
Ph. Ellia, On the distance between perfect numbers, J. of Combinatorics and Number Theory, vol.4, n.2, 105-108 (2012).
Ph. Ellia and P. Menegatti, Ramanujan-Nagell type equations and perfect numbers, arXiv 1406.2183, Jun 09 2014.
(Mma) p = Select[Prime[Range[11]], PrimeQ[2^# - 1] &]; t = 2^(p-1)*(2^p-1); Join[{0}, Sort[Flatten[Table[t[[i]] - t[[j]], {i, 2, Length[t]}, {j, i-1}]]]]
Cf. A000396 (perfect numbers), A139228 (first differences of perfect numbers).
nonn
T. D. Noe, Jun 09 2014