174592

Appears in sequences

• a(n) = 2^(n-1)*(2^n - (-1)^n)/3.at n=10A003683
• a(n) = n^2*(n^2 - 1)/6.at n=32A008911
• Number of Barlow packings with group R3(bar)m(O) that repeat after 6n layers.at n=17A011955
• Numbers that can be written as k/d(k) in four or more ways, where d(k) = number of divisors of k.at n=18A051346
• Numbers n such that n*sigma(n) is a perfect square.at n=23A069070
• Trinomial transform of Lucas numbers (A000032).at n=7A082762
• Admirable numbers that set a new record for largest subtracted divisor.at n=10A109745
• Starting a priori with the fraction 1/1, the denominators of fractions built according to the rule: add top and bottom to get the new bottom, add top and 9 times the bottom to get the new top.at n=8A110953
• Abundant numbers n such that n/(sigma(n)-2n) is an integer.at n=38A153501
• Terms of A181666 of the form 3*k+1.at n=31A172126
• Number of arrangements of n indistinguishable balls in n boxes with the maximum number of balls in any box equal to n-3.at n=28A180293
• Abundant numbers n for which the abundance d = sigma(n) - 2*n is a proper divisor, that is, 0 < d < n and d | n.at n=36A181595
• Let d_1=1 < d_2 < d_3 < ... be the divisors of n; sequence lists positive numbers n such that for some k, n = 2(d_1 + ... + d_k).at n=12A185961
• Numbers n such that gcd(sigma(n), n) > gcd(sigma(m), m) for all m < n.at n=13A216793
• Numbers n such that n = k/d(k) has exactly 4 solutions, where d(k) = number of divisors of k.at n=16A217125
• Numbers k for which sigma(k)/k - 1/4 is an integer.at n=4A218404
• Numbers k such that k divides sigma(3*k).at n=19A227303
• Numbers k such that sigma(k) mod k = antisigma(k) mod k, where sigma(k) = A000203(k) = sum of divisors of k, antisigma(k) = A024816(k) = sum of non-divisors of k.at n=7A229088
• Numbers n such that (n(n+1)/2) modulo sigma(n) = n.at n=21A232538
• Terms of A050973 that give maximum record values for A050973(k)/A050972(k).at n=6A236355