1,1
a(5) > 10^12. 2733834545701 and 232630479398401 are also terms. - Donovan Johnson, Nov 03 2011
J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
Cf. A007593.
Sequence in context: A004226 A070192 A178267 * A145123 A068258 A075407
Adjacent sequences: A028496 A028497 A028498 * A028500 A028501 A028502
nonn
Jud McCranie (JudMcCranie(AT)ugaalum.uga.edu)