88520

Appears in sequences

• a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), with a(1) = 1, a(2) = 2, and a(3) = 1.at n=17A049950
• a(1)=1. a(n) = Sum_{1<=k<n, gcd(k,n(n+1))=1} a(k).at n=45A125596
• a(n) = (n + 1)*(4*n^2 + 14*n + 9)/3.at n=39A268484