A110456 Largest prime obtained by concatenation of parts of a distinct partition of n. 0 if no such number exist.

0, 2, 3, 31, 41, 0, 421, 521, 0, 4231, 5231, 0, 7321, 8231, 0, 64231, 74231, 0, 94321, 431021, 0, 754123, 854213, 0, 5431021, 6421013, 0, 8431021, 9431021, 0, 65412103, 75411023, 0, 95421103, 96412103, 0, 643110211, 765324101

Offset

1,2

Comments

Conjecture a(n) = 0 only for n = 1, or n == 0 (mod 3), n is > 3. Subsidiary sequence (hard): Number of primes generated by concatenation of distinct partitions of n.

Links

Table of n, a(n) for n=1..38.

Example

Distinct partitions of 10 are 10,(9,1), (8,2), (7,3),...(7,2,1),(6,3,1),(5,3,2),...(4,3,2,1), etc. (4231 is the largest number obtained as a concatenation of (4,2,3,1).
a(10)=4231.

Crossrefs

Sequence in context: A272043 A136150 A155056 * A128348 A029973 A344736

Adjacent sequences: A110453 A110454 A110455 * A110457 A110458 A110459

Keyword

base,nonn

Author

Amarnath Murthy, Aug 04 2005

Extensions

Corrected and extended by R. J. Mathar, Feb 08 2008

Status

approved