a(n) is the least number that occurs exactly n times in A075255.

Terms

a(0) =4a(1) =2a(2) =1a(3) =11a(4) =35a(5) =71a(6) =791a(7) =2015a(8) =1259a(9) =9359a(10) =7559a(11) =15590a(12) =42839a(13) =75599a(14) =110159a(15) =251999a(16) =262079a(17) =576575a(18) =393119a(19) =453599a(20) =665279a(21) =1713599