Numbers k such that (Sum_{i=1..k} d(i)^2) / k is an integer, where d(i) is the number of divisors of i.
A186452
Numbers k such that (Sum_{i=1..k} d(i)^2) / k is an integer, where d(i) is the number of divisors of i.
Terms
- a(0) =1a(1) =3a(2) =7a(3) =19a(4) =27a(5) =83a(6) =432a(7) =1036a(8) =1043a(9) =1501a(10) =2502a(11) =3846a(12) =19549a(13) =272607a(14) =937831a(15) =1264523a(16) =2583451a(17) =3155016a(18) =3518511a(19) =23042324a(20) =43689125a(21) =67584692a(22) =151289679a(23) =700257471a(24) =1064015859a(25) =1246557270a(26) =4797982637a(27) =7975748869a(28) =50374519346
External references
- oeis: A186452