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A213737
Odd numbers whose set of prime factors (taken with multiplicity) uses each digit from 0 to 9 exactly once.
1
42279945, 42315045, 42514845, 43092645, 43767645, 45981645, 46149045, 46321845, 52226745, 52654695, 53159595, 56789745, 56841045, 57321645, 58193745, 59869345, 61277145, 61421595, 61860445, 62146545, 62866645, 62936295, 62969845, 63395295, 63411595
OFFSET
1,1
COMMENTS
This sequence also contains numbers not ending in 5 (i.e., 78369189).
a(1916) = 240510701 is the first semiprime with this property.
No pandigital number is in the sequence.
LINKS
Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000
Wikipedia, Prime factor
EXAMPLE
42279945 = 3*5*1049*2687 is in the sequence since the set {3, 5, 1049, 2687} can be formed from the digits 0 to 9 and each digit is used only once.
MATHEMATICA
lst = {}; Do[If[Equal[Sort@Flatten@IntegerDigits@FactorInteger[n][[All, {1}]], {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}] && SquareFreeQ[n], AppendTo[lst, n]], {n, 4*10^7 + 1, 7*10^7, 2}]; lst
ed1Q[n_]:=Module[{fi=FactorInteger[n]}, Max[Transpose[fi][[2]]]==1 && Union[ Flatten[IntegerDigits/@Transpose[fi][[1]]]]==Range[0, 9]]; Select[Range[ 4*10^7+ 1, 6.4*10^7, 2 ], ed1Q] (* Harvey P. Dale, Dec 19 2014 *)
CROSSREFS
Subsequence of A058909.
Sequence in context: A198168 A218109 A263561 * A254091 A254098 A276714
KEYWORD
base,fini,nonn
AUTHOR
STATUS
approved