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A119263
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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 non-squarefree positive integers within each run of non-squarefree integers.
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0
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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; internal format)
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OFFSET
| 1,1
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COMMENTS
| Sequence is its own inverse permutation.
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EXAMPLE
| The run of non-squarefree integers (27,28) becomes (28,27). And the run of squarefree integers (29,30,31) becomes (31,30,29).
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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)
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CROSSREFS
| Sequence in context: A105033 A092486 A159966 * A028412 A156699 A077819
Adjacent sequences: A119260 A119261 A119262 * A119264 A119265 A119266
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KEYWORD
| nonn
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AUTHOR
| Leroy Quet Jul 23 2006
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EXTENSIONS
| More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 16 2006
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