a(n) is the least number with exactly n prime factors, counted with multiplicity, that is the concatenation of x, 1, and x for some x.

A392239

a(n) is the least number with exactly n prime factors, counted with multiplicity, that is the concatenation of x, 1, and x for some x.

Terms

    a(0) =313a(1) =111a(2) =212a(3) =414a(4) =616a(5) =40140a(6) =28128a(7) =76176a(8) =1841184a(9) =60160a(10) =4001400a(11) =9201920a(12) =126411264a(13) =6641664a(14) =280012800a(15) =11614111614a(16) =894418944a(17) =40288140288a(18) =74080174080a(19) =24928124928

External references