437745

Appears in sequences

• Numbers k such that sigma(k) = sigma(k+9).at n=10A015877
• f-perfect numbers, where f(m) = m - 1.at n=6A066230
• The floor(n/2)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218.at n=11A066240
• Odd numbers n such that abs(sigma(n)-2n) <= n^(1/3). Abundance-radius = abs(sigma(n)-2n) does not exceed cubic root of n and n is odd.at n=12A088010
• Odd admirable numbers: such that sigma(n) = 2n + 2d for some d | n.at n=30A109729
• Odd unitary admirable numbers: the odd terms of A328328.at n=4A329188
• Odd bi-unitary admirable numbers: the odd terms of A334972.at n=8A334973
• Odd infinitary admirable numbers: the odd terms of A334974.at n=7A334975
• Odd unitary abundant numbers whose unitary abundancy is closer to 2 than that of any smaller odd unitary abundant number.at n=26A335052
• Odd bi-unitary abundant numbers whose bi-unitary abundancy is closer to 2 than that of any smaller odd bi-unitary abundant number.at n=19A335053
• Odd infinitary abundant numbers whose infinitary abundancy is closer to 2 than that of any smaller odd infinitary abundant number.at n=20A335055
• Primitive unitary abundant numbers k (A302573) whose unitary abundancy index usigma(k)/k has a record low value.at n=10A362054
• Numbers m with abundance 30: sigma(m) - 2*m = 30.at n=4A389701