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A176555
Noncomposite concatenations of divisors of some k, ordered by k.
2
1, 13, 17, 139, 113, 13721, 131, 137, 167, 173, 179, 197, 1103, 1109, 111121, 1151, 1163, 1181, 1361183, 1193, 1373219, 1223, 1229, 1379237, 1277, 1283, 1307, 131133121363, 1367, 1373, 13127381, 1409, 1433, 1439, 13157471, 1487, 13163489
OFFSET
1,2
COMMENTS
Intersection of A037278 and A018252.
FORMULA
a(n) = A037278(A176553(n)).
EXAMPLE
For n = 6; a(6) = 13721 because A176553(6) = 21, and divisors of 21 are 1, 3, 7, 21; concatenation of divisors A037278(21) = 13721 is noncomposite number.
CROSSREFS
Sequence in context: A210547 A202136 A123909 * A237423 A342725 A292003
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Apr 20 2010
EXTENSIONS
Extended and edited by Charles R Greathouse IV, Apr 27 2010
STATUS
approved