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A147870
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Number of steps required to erase a finite sequence of nonnegative integers in the following way: at the n-th step, if the last number of the string is 0, delete it; otherwise replace it with n copies of the next-smaller number.
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0
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OFFSET
| 0,2
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COMMENTS
| The fifth term is much larger than Skewes's number.
The starting string for a(n) is the length 1 string containing n.
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LINKS
| Sudoku.com, off-topic, How NOT to erase pencil-marks! [From Martin Chan (martin.chan(AT)westminster.org.uk), Jun 06 2010]
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EXAMPLE
| 3 is erased in 14 steps:
3->2->11->1000->100->10->1->0000000->000000->00000->0000->000->00->0->x
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CROSSREFS
| Sequence in context: A132531 A123052 A064773 * A199931 A163361 A196239
Adjacent sequences: A147867 A147868 A147869 * A147871 A147872 A147873
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KEYWORD
| nonn
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AUTHOR
| Martin Chan (martin.chan(AT)westminster.org.uk), Nov 16 2008
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