A230034 Numbers which can't be represented as a sum of 3 relatively prime positive integers such that each pair of them is not coprime.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 50, 51, 52, 54, 56, 57, 58, 60, 62, 63, 64, 66, 68, 70, 72, 74, 75, 76, 78

Offset

1,2

Comments

Complement of A230035.

Sequence is finite and contains exactly 156 terms.

Generally for every positive integer k there is only a finite quantity of numbers which can't be represented as a sum of k + 1 relatively prime positive integers such that any k of them are not coprime.

For instance, for k = 3, 570570 is the largest number which cannot be represented.

Links

Vladimir Letsko, Table of n, a(n) for n = 1..156 [uploaded as b-file by Georg Fischer, Aug 24 2020]

Vladimir Letsko, Table of n, a(n) for n=1..156 (full sequence, source for b-file)

Example

Every positive integer less than 31 is in the sequence because 31 obviously is the least number which can be represented as 2*3 + 2*5 + 3*5, i.e. as a sum of 3 relatively prime positive integers such that every pair of them is not coprime.

Crossrefs

Cf. A230035.

Sequence in context: A247064 A160547 A348520 * A269331 A246103 A281873

Adjacent sequences: A230031 A230032 A230033 * A230035 A230036 A230037

Keyword

nonn,fini,full

Author

Vladimir Letsko, Dec 20 2013

Status

approved