50871

Appears in sequences

• Numbers k such that j(k)*phi(k) = sigma(phi(k)), j(k) = A033831(k).at n=38A033856
• a(n) = Sum{a(k): k=0,1,2,...,n-4,n-2,n-1}; a(n-3) is not a summand; initial terms are 0,2,3.at n=18A049861
• Inverse of A304755: if A304755(k) = n, a(n) = k, or 0 if n does not occur in A304755.at n=28A304756