1,1

Numbers m such that 2 <= sigma(m) / m < 3.

Supersequence of A000396 (perfect numbers).

Jaroslav Krizek and T. D. Noe, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Abundancy

Eric Weisstein's World of Mathematics, Abundant Number

Number 70 is in sequence because sigma(70) / 70 = 144 / 70, which is between 2 and 3.

Cf. A204828 (abundant numbers with abundancy 3 <= a < 4).

Sequence in context: A326133 A177052 A023196 * A005835 A007620 A100715

Adjacent sequences: A204826 A204827 A204828 * A204830 A204831 A204832

nonn

Jaroslav Krizek, Jan 22 2012

approved