1,1
a(1) and a(2) and a(5) are 3 multiple perfect numbers. a(4)=S(a(3)).
Eric Weisstein's World of Mathematics, WathWorld
Sequence in context: A152622 A100145 A090216 this_sequence A166069 A114887 A069085
Adjacent sequences: A113543 A113544 A113545 this_sequence A113547 A113548 A113549
nonn
Yasutoshi Kohmoto zbi74583(AT)boat.zero.ad.jp, Jan 27 2006
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