a(n) is the least number k such that the sequence of elements of the continued fraction of the harmonic mean of the divisors of k is palindromic with length n, or -1 if no such k exists.

A349478

a(n) is the least number k such that the sequence of elements of the continued fraction of the harmonic mean of the divisors of k is palindromic with length n, or -1 if no such k exists.

Terms

    a(0) =1a(1) =15a(2) =8a(3) =545a(4) =21a(5) =1131a(6) =16a(7) =98124a(8) =28676a(9) =1109305a(10) =28672a(11) =16837500a(12) =1231932a(13) =477021580a(14) =6129711a(15) =734420331a(16) =441972042a(17) =4343866215a(18) =42741916965a(19) =96692841558a(20) =2193739177

External references