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A336768
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Irregular triangle where the n-th row list the positive integers which can be written in two bases smaller than n as mutually-reversed strings of digit(s), for n>=4.
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2
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1, 1, 2, 22, 1, 2, 3, 7, 22, 1, 2, 3, 4, 7, 22, 87, 9831, 1, 2, 3, 4, 5, 7, 9, 17, 22, 51, 87, 102, 2601, 9831, 314767045, 1, 2, 3, 4, 5, 6, 7, 9, 17, 22, 51, 87, 91, 102, 220, 2601, 5258, 7491, 8283, 9831, 10516, 13541, 15774, 16566, 71500, 644765, 3552340, 314767045, 1427310725, 1848187230, 1916060910
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OFFSET
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4,3
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COMMENTS
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Note that the last row with index 9 may still be incomplete.
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LINKS
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EXAMPLE
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Triangle begins:
4| 1;
5| 1, 2, 22;
6| 1, 2, 3, 7, 22;
7| 1, 2, 3, 4, 7, 22, 87, 9831;
8| 1, 2, 3, 4, 5, 7, 9, 17, 22, 51, 87, 102, 2601, 9831, 314767045;
9| 1, 2, 3, 4, 5, 6, 7, 9, 17, 22, 51, 87, 91, 102, 220, 2601, 5258, 7491, ...
...
For n=4, there is a single integer whose base 2 and base 3 representations are each other reverse: it is 1 which is its own reverse.
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CROSSREFS
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KEYWORD
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nonn,base,tabf
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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