OFFSET
0,7
COMMENTS
Number of pairwise non-coprime strict compositions of n.
EXAMPLE
The a(2) = 1 through a(15) = 7 compositions (A..F = 10..15):
2 3 4 5 6 7 8 9 A B C D E F
24 26 36 28 2A 2C 3C
42 62 63 46 39 4A 5A
64 48 68 69
82 84 86 96
93 A4 A5
A2 C2 C3
246 248
264 284
426 428
462 482
624 824
642 842
MATHEMATICA
stabQ[u_, Q_]:=And@@Not/@Q@@@Tuples[u, 2];
Table[Length[Join@@Permutations/@Select[IntegerPartitions[n], UnsameQ@@#&&stabQ[#, CoprimeQ]&]], {n, 0, 30}]
CROSSREFS
A318717 is the unordered version.
A318719 is the version for Heinz numbers of partitions.
A337561 is the pairwise coprime instead of pairwise non-coprime version, or A337562 if singletons are considered coprime.
A337605*6 counts these compositions of length 3.
A337696 ranks these compositions.
A101268 counts pairwise coprime or singleton compositions.
A233564 ranks strict compositions.
A333228 ranks compositions whose distinct parts are pairwise coprime.
A335236 ranks compositions neither a singleton nor pairwise coprime.
A337462 counts pairwise coprime compositions.
A337694 lists numbers with no two relatively prime prime indices.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Oct 06 2020
STATUS
approved