A090705 Lexicographically earliest permutation of squarefree numbers with mu(a(n)) = -(-1)^n, where mu = A008683.

1, 2, 6, 3, 10, 5, 14, 7, 15, 11, 21, 13, 22, 17, 26, 19, 33, 23, 34, 29, 35, 30, 38, 31, 39, 37, 46, 41, 51, 42, 55, 43, 57, 47, 58, 53, 62, 59, 65, 61, 69, 66, 74, 67, 77, 70, 82, 71, 85, 73, 86, 78, 87, 79, 91, 83, 93, 89, 94, 97, 95, 101, 106, 102, 111, 103, 115, 105, 118

Offset: 1

Author

Reinhard Zumkeller, Jan 01 2005

Keywords

• nonn

Comments

a(n) = A102510(A005117(n)).

Links

• Ivan Neretin, Table of n, a(n) for n = 1..1000
• Eric Weisstein's World of Mathematics, Squarefree

Crossrefs

Cf. A005117, A102511.

Programs

Mathematica

mx = 70; m = Select[Range[2 mx], SquareFreeQ]; m1 = Select[m, MoebiusMu[#] == 1 &]; m2 = Complement[m, m1]; a = Flatten[Transpose[{Take[m1, mx/2], Take[m2, mx/2]}]] (* Ivan Neretin, May 18 2015 *)