A382964 Number of k <= n such that rad(k) divides n and g * k > n where g is the largest prime factor of n and rad = A007947.
0, 1, 1, 1, 1, 3, 1, 1, 1, 4, 1, 4, 1, 4, 3, 1, 1, 5, 1, 5, 3, 5, 1, 5, 1, 5, 1, 5, 1, 12, 1, 1, 4, 6, 3, 6, 1, 6, 4, 6, 1, 14, 1, 6, 4, 6, 1, 6, 1, 6, 4, 6, 1, 6, 3, 6, 4, 6, 1, 16, 1, 6, 4, 1, 3, 17, 1, 7, 4, 13, 1, 7, 1, 7, 4, 7, 3, 18, 1, 7, 1, 7, 1, 19, 3
Offset: 1
Keywords
Examples
Table of select n, a(n), and numbers k in row n of A382926: n a(n) row n of A382926 -------------------------------------------------------- 6 3 3, 4, 6; 10 4 4, 5, 8, 10; 12 4 6, 8, 9, 12; 14 4 4, 7, 8, 14; 15 3 5, 9, 15; 18 5 8, 9, 12, 16, 18; 20 5 5, 8, 10, 16, 20; 21 3 7, 9, 21; 22 5 4, 8, 11, 16, 22; 24 5 9, 12, 16, 18, 24; 26 5 4, 8, 13, 16, 26; 28 5 7, 8, 14, 16, 28; 30 12 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 27, 30.
Links
- Michael De Vlieger, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
(* First, run the "regs" function from A369609, then: *) Table[Count[regs[n], _?(Function[k, AllTrue[FactorInteger[n][[All, 1]], #*k > n &]])], {n, 105}]