178560

Appears in sequences

• Sum of divisors of those numbers n such that n and n+1 have the same sum of divisors.at n=26A053215
• Theta series of 9-dimensional odd unimodular lattice E_8 + Z.at n=15A071967
• Sigma(A033631(n)) {sigma is the sum of divisors function A000203}.at n=21A115619
• Aliquot sequence starting at 3630.at n=17A143930
• Triangle T(n, k) = [x^k](p(x, n, q)) where p(x,n,q) = Product_{j=1..n} (x + q^j) + Product_{j=1..n} (x*q^j + 1), p(x, 0, q) = 1, and q = 2, read by rows.at n=24A173048
• Average of amicable pairs (x,y), ordered by the smaller value x given in A002025.at n=19A275315
• Average of amicable pairs (x,y), ordered by the sum x+y given in A259953.at n=19A275316
• Numbers m such that the equation m = k*sigma(k) has more than one solution.at n=10A337873