26486

Appears in sequences

• Numbers n such that sigma(n)=sigma(d_1)*sigma(d_2)*...*sigma(d_k) where d_1 d_2 ... d_k is the decimal expansion of n.at n=18A098771
• a(n) = Sum_{k=1..n} (k+2)!/k! = Sum_{k=1..n} (k+2)*(k+1).at n=41A180118
• a(n) = pg(3, n) + pg(4, n) + ... + pg(n, n) where pg(m, n) is the n-th m-th-order polygonal number.at n=19A241452
• Number of 7-element subsets of [n] whose sum is a triangular number.at n=17A320853