

A118081


Even numbers that can't be represented as the sum of two odd composite numbers.


6



2, 4, 6, 8, 10, 12, 14, 16, 20, 22, 26, 28, 32, 38
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OFFSET

1,1


COMMENTS

Suggested by the familiar puzzle, "What is the largest even number that is not the sum of two odd composite numbers?" The sequence contains all even numbers that are not of the form (9+6k)+9, (9+6k)+25, or (9+6k)+35, where k is a nonnegative integer.
If 1 is allowed as a composite number, then only the eight numbers in A046458 are not representable.  T. D. Noe, Jun 01 2008


LINKS



EXAMPLE

38 is in the sequence because 38 == 2 (mod 3) and all even numbers congruent to 2 mod 3 larger than 38 can be expressed as the sum of odd composites (9+6k) and 35, where k is a nonnegative integer.


CROSSREFS



KEYWORD

fini,full,nonn


AUTHOR



STATUS

approved



