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A108343
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Gapful numbers >= 100: numbers that are divisible by the number formed by their first and last digit. Numbers up to 100 trivially have this property and are excluded.
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2
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100, 105, 108, 110, 120, 121, 130, 132, 135, 140, 143, 150, 154, 160, 165, 170, 176, 180, 187, 190, 192, 195, 198, 200, 220, 225, 231, 240, 242, 253, 260, 264, 275, 280, 286, 297, 300, 315, 330, 341, 352, 360, 363, 374, 385, 390, 396, 400, 405, 440, 451
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OFFSET
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1,1
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LINKS
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EXAMPLE
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253 is in the sequence because 253 = 11 * 23 and 23 is the concatenation of 2 and 3 (first and last digit of 253).
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MATHEMATICA
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fQ[ n_ ] := Block[ {id = IntegerDigits[ n ]}, IntegerQ[ n / FromDigits[ {id[ [ 1 ] ], id[ [ -1 ] ]} ] ] ]; Select[ Range[ 100, 461 ], fQ[ # ] & ] (* Robert G. Wilson v, Jul 19 2005 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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