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Search: id:A085944
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| A085944 |
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Let S = 12345678901234567890123456..., the cyclic concatenation of digits; partition this string into distinct squarefree numbers. To avoid leading zeros, no member may end with the digit 9. |
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+0
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| 1, 2, 3, 4567, 890, 123, 45678, 901, 23, 4567890, 1234, 5, 6, 7, 89012345, 67, 89012345678, 90123, 45678901, 2345, 678, 901234, 5678, 9012345, 67890, 12345, 678901, 2345678, 901234567, 8901234567890, 1234567, 8901234567890123
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OFFSET
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1,2
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EXAMPLE
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a(4) = 4567 because 4567 is squarefree, while 4, 45 and 456 are not.
a(5) = 890 because 89 would cause a(6) to have a leading 0.
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PROGRAM
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(PARI) used = matrix(9, 60); x = 1; for (n = 1, 80, num = x; s = x; d = 1; while (used[s, d] || !issquarefree(num) || x == 9, x = (x + 1)%10; num = 10*num + x; d++); print(num); used[s, d] = 1; x++); (Wasserman)
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CROSSREFS
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Cf. A085943.
Sequence in context: A085943 A068661 A068826 this_sequence A137078 A146026 A115640
Adjacent sequences: A085941 A085942 A085943 this_sequence A085945 A085946 A085947
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 14 2003
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EXTENSIONS
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Corrected and extended by David Wasserman (wasserma(AT)spawar.navy.mil), Feb 14 2005
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