104168

Appears in sequences

• Numbers k such that phi(k) and sigma(k) are both perfect squares.at n=29A067781
• Number of positive integers <= 10^n that are divisible by no prime exceeding 5.at n=39A106598
• A Lucas-Binet triangle read by rows: t(n,m)=((( 1 + Sqrt[Prime[n]]))^m + (( 1 - Sqrt[Prime[n]]))^m)/2.at n=42A140895
• Number of nondecreasing arrangements of 5 nonzero numbers in -(n+3)..(n+3) with sum zero.at n=29A188335
• Numbers m such that sigma(m)*tau(m) is a square but sigma(m)/tau(m) is not an integer.at n=27A327831