5405400

Appears in sequences

• Four numbers (a,b,c,d) with a<b<c<d that satisfy sigma(a) = sigma(b) = sigma(c) = sigma(d) = a+b+c+d are called an amicable quadruple. We order these quadruples according to the common value of sigma. The values of (a, b, c, d, sigma) are in (this sequence, A036472, A036473, A036474, A116148) respectively.at n=5A036471
• LCM of numbers m such that 1 <= m <= n, m has a common factor with n, but m does not divide n.at n=44A066575
• a(n) = n*lcm{1,2,...,n}.at n=14A081528
• Smallest integer value of n!/(m_1!*m_2!*...*m_k!), where 1=m_1 < m_2 < ... is the sequence of integers coprime to n.at n=14A088303
• Smallest numbers having exactly n divisors d>1 such that also d+1 is a divisor.at n=30A088726
• Members of A097212, excluding highly composite numbers (A002182).at n=10A097213
• Numerator of the harmonic mean of the first n positive integers.at n=14A102928
• Where records occur in A018892.at n=38A126098
• Numbers that are products of distinct primorial numbers (see A002110).at n=36A129912
• Earliest sequence such that xy | a(x+y) for all x>=1, y>=1.at n=14A169900
• Triangle S(n, k) by rows: coefficients of 2^((n-1)/2)*(x^(1/2)*d/dx)^n, where n = 1, 3, 5, ...at n=31A223523
• If 2n = 2^e1 + 2^e2 + ... + 2^ek [e1 .. ek distinct], then a(n) = A002110(e1) * A002110(e2) * ... * A002110(ek).at n=38A283477
• Least k such that the number of pairs of consecutive divisors of k equals n.at n=31A287142
• Number of relaxed compacted binary trees of right height at most one with empty initial and final sequence on level 0.at n=9A288950
• Determinant of n X n matrix whose main diagonal consists of the first n 6-gonal numbers and all other elements are 1's.at n=5A302910
• Highly Brazilian numbers (A329383) that are not highly composite numbers (A002182).at n=5A309493
• Numbers that are a smallest number with k pairs of successive divisors, for some k.at n=32A328450
• a(n) is the least positive integer divisible by exactly n primitive nondeficient numbers (A006039).at n=20A337691
• Infinitary arithmetic numbers k whose mean infinitary divisor is an infinitary divisor of k.at n=27A361387
• Numbers with a record number of exponentially squarefree divisors.at n=27A365681