53121

Appears in sequences

• A triangle related to the a(n) formulas for the rows of the ED2 array A167560.at n=40A167565
• The fifth left hand column of triangle A167565.at n=4A168304
• Discriminants of totally real cubic fields in which every norm-positive unit is totally positive.at n=6A329769
• a(n) = floor(1/(1-s(n))) where s(n) = Sum_{k=1..n} phi(k)/k * log(2^k/(2^k-1)). phi(k) is the Euler totient function A000010(k).at n=14A383024