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A057153
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Construct difference array so that (1) first row begins with 1, (2) every row is monotonic increasing, (3) no number appears more than once, (4) smallest number not yet used begins a new row. Sequence gives first row of array.
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10
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1, 3, 9, 26, 73, 194, 485, 1150, 2617, 5779, 12497, 26653, 56355, 118545, 248605, 520365, 1087853, 2272770, 4748677, 9930475, 20800122, 43658310, 91836751, 193549010, 408449129, 862455193, 1820771343, 3840569196, 8089327515
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OFFSET
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1,2
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COMMENTS
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This is the limit of the family of sequences starting with A005228, A037257, A037260. Adjoin next free number as the first element in a new level of differences unless it would produce a duplicate in which case ignore.
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LINKS
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FORMULA
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EXAMPLE
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Array begins
1 3 9 26 73 194 ...
.2 6 17 47 121 ...
. 4 11 30 74 ...
.. 7 19 44 ...
... 12 25 ...
.... 13 ...
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PROG
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(Haskell)
a057153 n = a056230_tabl !! (n-1) !! (n-1)
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CROSSREFS
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KEYWORD
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nice,nonn,easy
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AUTHOR
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EXTENSIONS
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More terms from Rob Speer (rob(AT)twcny.rr.com) and Loren Merritt, Aug 14 2000
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STATUS
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approved
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