A087558 - OEIS

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A087558

a(n) = largest prime that is the concatenation of two numbers whose product is n.

11, 0, 31, 41, 0, 61, 71, 0, 19, 101, 0, 43, 131, 0, 151, 0, 0, 181, 191, 0, 211, 211, 0, 241, 251, 0, 271, 281, 0, 103, 311, 0, 331, 0, 0, 0, 137, 0, 313, 401, 0, 421, 431, 0, 59, 461, 0, 163, 491, 0, 317, 521, 0, 541, 0, 0, 571, 229, 0, 601, 0, 0, 631, 641, 0, 661, 167, 0, 691

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OFFSET

2,1

COMMENTS

a(3k+2) = 0. - David Wasserman, Jun 07 2005

LINKS

Table of n, a(n) for n=2..70.

EXAMPLE

a(10) = 101, the pair of complementary factors of 10 are (1,10), (2,5) and the prime obtained is 101.

CROSSREFS

Cf. A087557.

Sequence in context: A274851 A075360 A256756 * A087555 A185682 A217752