351351

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= n/2.at n=25A047163
• Number of nonempty subsets of {1,2,...,n} in which exactly 3/4 of the elements are <= n/2.at n=25A047164
• Odd abundant numbers not divisible by 5.at n=10A064001
• Odd numbers which can be written in precisely one way as sum of a subset of their proper divisors.at n=2A065235
• The floor(n/3)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218.at n=14A066238
• 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=10A088010
• Odd admirable numbers: such that sigma(n) = 2n + 2d for some d | n.at n=23A109729
• Admirable numbers such that the subtracted divisor is square.at n=25A109806
• Odd abundant numbers (A005231) which are not in A136446, i.e., not sum of some of their proper divisors > 1.at n=0A122036
• Partial sum of A005915.at n=25A126274
• Odd numbers whose abundancy is closer to 2 than any smaller odd number.at n=13A171929
• Odd abundant numbers whose abundancy is closer to 2 than any smaller odd abundant number.at n=7A188263
• Numbers k whose abundance is 18: sigma(k) - 2*k = 18.at n=4A223610
• Numbers k such that sigma(k) == 0 (mod k+9).at n=5A274563
• Least odd primitive abundant number having its prime signature.at n=22A316116
• Terms of A083209 with a record number of divisors.at n=8A337739
• Primitive nondeficient numbers sorted by largest prime factor then by increasing size. Irregular triangle T(n, k), n >= 2, k >= 1, read by rows, row n listing those with largest prime factor = prime(n).at n=30A338133
• a(n) = Sum_{k=0..floor((n-1)/3)} Stirling1(n,3*k+1).at n=10A357835
• Primitive abundant numbers for which there is no smaller primitive abundant number having the same ordered prime signature.at n=36A357921
• Odd abundant numbers that are also doublets (cf. A020338).at n=17A380232