123152

Appears in sequences

• Larger of amicable pair.at n=15A002046
• Amicable numbers.at n=29A063990
• Largest members of k-sociable cycles of order r.at n=22A183013
• Numbers k such that sigma(k) = sigma(sigma(k)-k).at n=33A206708
• Deficient numbers whose aliquot sequence is deficient, abundant, deficient, ..., etc.at n=28A234970
• Let us denote 's' the sum of the deficient numbers in the aliquot parts of x. Sequence lists numbers x such that sigma(s)-s is equal to x.at n=23A254879
• Amicable pairs.at n=31A259180
• Amicable pairs (x < y) ordered by nondecreasing sum (x + y) and then by increasing x.at n=29A259933
• Larger of amicable pair (x, y) as they are listed in A259933.at n=14A260087
• Amicable pairs of even numbers.at n=21A262622
• Even amicable numbers.at n=21A262624
• Twin amicable numbers (m,n) where there is not any part of another amicable pair between m and n.at n=19A273259
• List of pairs of amicable numbers (m,n) where the sum of the pair is divisible by 10.at n=17A291422
• Amicable pairs with the property that both members have the same number of divisors.at n=13A328064
• E.g.f. A(x) satisfies A(x) = exp(2 * x / (1 - x*A(x))) / (1 - x*A(x)).at n=5A380916
• Integers k such that there exists an integer 0<m<k such that m*sigma(m)^2 + k*sigma(k)^2 = (m+k)^3.at n=16A383714
• Integers k such that there exists an integer 0<m<k such that sigma(m)^2 + sigma(k)^2 = 2*(m+k)^2.at n=30A385008
• Numbers y such that there exists an integer 0 < x < y such that sigma(x)^x * sigma(y)^y = (x+y)^(x+y).at n=15A385186