A102511 -id:A102511 - cp's OEIS frontend

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

Reinhard Zumkeller, Jan 01 2005

nonn

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

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

Cf. A005117, A102511.

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 *)

A102510 If n is squarefree then A090705(A100112(n)) else n.

Original entry on oeis.org

1, 2, 6, 4, 3, 10, 5, 8, 9, 14, 7, 12, 15, 11, 21, 16, 13, 18, 22, 20, 17, 26, 19, 24, 25, 33, 27, 28, 23, 34, 29, 32, 35, 30, 38, 36, 31, 39, 37, 40, 46, 41, 51, 44, 45, 42, 55, 48, 49, 50, 43, 52, 57, 54, 47, 56, 58, 53, 62, 60, 59, 65, 63, 64, 61, 69, 66, 68, 74, 67, 77, 72

Offset: 1

Reinhard Zumkeller, Jan 13 2005

nonn

a(A005117(n)) = A090705(n) and a(A013929(n)) = A013929(n);
A102511(n) = Sum(A008683(a(k)): k<=n) <= 1;
permutation of the natural numbers with inverse A102513;
A102512 = a(a(n)).

Index entries for sequences that are permutations of the natural numbers

Cf. A005117, A008966.

cp's OEIS Frontend

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

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