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A059469
Numbers that are the products of distinct substrings of themselves.
1
110, 125, 210, 250, 310, 360, 375, 410, 510, 520, 610, 710, 735, 810, 910, 1000, 1010, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090, 1100, 1110, 1197, 1210, 1250, 1280, 1296, 1310, 1352, 1410, 1510, 1520, 1593, 1610, 1710, 1734, 1750, 1810, 1910, 2010
OFFSET
1,1
LINKS
EXAMPLE
a(1) = 110 = 11*10; a(10) = 520 = 52*5*2; a(13) = 735 = 35*7*3.
MATHEMATICA
okQ[n_] := Module[{dd, nn}, If[n == 1 || PrimeQ[n], Return[False]]; dd = IntegerDigits[n]; nn = FromDigits /@ Flatten[Table[dd[[i ;; j]], {i, 1, Length[dd]}, {j, i, Length[dd]}], 1] // Union // Most // Select[#, # != 0 && Divisible[n, #]&]&; MemberQ[Times @@@ Subsets[nn], n]];
Select[Range[38110], okQ] (* Jean-François Alcover, Aug 19 2019 *)
CROSSREFS
Sequence in context: A274945 A274944 A275343 * A114068 A073494 A073488
KEYWORD
nice,nonn,base
AUTHOR
Erich Friedman, Feb 03 2001
EXTENSIONS
Offset corrected, example extended, and b-file added by Reinhard Zumkeller, Sep 08 2008
STATUS
approved