

A087555


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


1



11, 0, 31, 41, 0, 61, 71, 0, 73, 101, 0, 211, 311, 0, 313, 107, 0, 811, 911, 0, 211, 1013, 0, 1213, 1511, 0, 1117, 1811, 0, 2011, 2111, 0, 2311, 2411, 0, 2017, 2711, 0, 2713, 3011, 0, 2617, 431, 0, 3511, 3413, 0, 3613, 3911, 0, 4111, 4211, 0, 541, 3917, 0, 4513, 4217
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OFFSET

2,1


COMMENTS

a(3k) = 0. Conjecture: No other term is zero.


LINKS

Table of n, a(n) for n=2..59.


EXAMPLE

a(10) = 73, the Partitions of 10 are (1,9), (2,8), 3,7), (4,6), (5,5) and the primes obtained are 19,37 and 73.


CROSSREFS

Cf. A087556.
Sequence in context: A075360 A256756 A087558 * A185682 A217752 A335646
Adjacent sequences: A087552 A087553 A087554 * A087556 A087557 A087558


KEYWORD

base,nonn


AUTHOR

Amarnath Murthy, Sep 13 2003


EXTENSIONS

More terms from David Wasserman, Jun 07 2005


STATUS

approved



