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A119263 A permutation of the positive integers made by (alternatingly) reversing the order of the squarefree positive integers within each run of squarefree integers and reversing the order of the nonsquarefree positive integers within each run of nonsquarefree integers. 0
3, 2, 1, 4, 7, 6, 5, 9, 8, 11, 10, 12, 15, 14, 13, 16, 17, 18, 19, 20, 23, 22, 21, 25, 24, 26, 28, 27, 31, 30, 29, 32, 35, 34, 33, 36, 39, 38, 37, 40, 43, 42, 41, 45, 44, 47, 46, 50, 49, 48, 51, 52, 53, 54, 55, 56, 59, 58, 57, 60, 62, 61, 64, 63, 67, 66, 65, 68, 71, 70, 69, 72 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Sequence is its own inverse permutation.
LINKS
EXAMPLE
The run of nonsquarefree integers (27,28) becomes (28,27). And the run of squarefree integers (29,30,31) becomes (31,30,29).
PROG
(PARI) {m=73; n=1; while(n<=m, k=n; while(issquarefree(n), n++); forstep(a=n-1, k, -1, print1(a, ", ")); k=n; while(!issquarefree(n), n++); forstep(a=n-1, k, -1, print1(a, ", ")))} \\ Klaus Brockhaus, Aug 16 2006
CROSSREFS
Sequence in context: A105033 A092486 A159966 * A028412 A156699 A245183
KEYWORD
nonn
AUTHOR
Leroy Quet, Jul 23 2006
EXTENSIONS
More terms from Klaus Brockhaus, Aug 16 2006
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)