A176556 Nonprime concatenations of divisors of some k, ordered by k.

1, 12, 124, 15, 1236, 1248, 12510, 111, 1234612, 12714, 13515, 124816, 117, 1236918, 119, 12451020, 121122, 123, 1234681224, 1525, 121326, 13927, 12471428, 129, 12356101530, 12481632, 131133, 121734, 15735, 123469121836, 121938, 131339

Offset

1,2

Comments

Intersection of A037278 and A018252.

Links

Table of n, a(n) for n=1..32.

Formula

a(n) = A037278(A176554(n)).

Example

For n = 6; a(6) = 1248 because A176554(6) = 8 and divisors of 8 are 1, 2, 4, 8; concatenation of divisors A037278(8) = 1248 is nonprime number.

Crossrefs

Sequence in context: A074158 A071269 A061088 * A175252 A173578 A291065

Adjacent sequences: A176553 A176554 A176555 * A176557 A176558 A176559

Keyword

nonn,base

Author

Jaroslav Krizek, Apr 20 2010

Extensions

Extended and edited by Charles R Greathouse IV, Apr 27 2010

Status

approved