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 A176553 a(n) = numbers m such that concatenations of divisors of m are noncomposites. 4
 1, 3, 7, 9, 13, 21, 31, 37, 67, 73, 79, 97, 103, 109, 121, 151, 163, 181, 183, 193, 219, 223, 229, 237, 27, 283, 307, 363, 367, 373, 381, 409, 433, 439, 471, 487, 489, 499, 511, 523, 571, 601, 603, 607, 63, 619, 657, 669, 709, 733, 787, 811, 817, 819, 823, 841, 867 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS See A037278(n) = concatenation of divisors of n. See A176555 for corresponding values of concatenations. Complement of A176554 (n) for n >= 2. LINKS EXAMPLE a(6) = 21: the divisors of 21 are 1,3,7,21, and their concatenation 13721 is noncomposite. CROSSREFS Sequence in context: A111250 A118643 A043772 * A109370 A018663 A110575 Adjacent sequences:  A176550 A176551 A176552 * A176554 A176555 A176556 KEYWORD nonn,base AUTHOR Jaroslav Krizek, Apr 20 2010 EXTENSIONS Edited and extended by Charles R Greathouse IV, Apr 30 2010 STATUS approved

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