OFFSET
0,5
EXAMPLE
The a(0) = 0 through a(6) = 8 compositions:
. . . . (13) (14) (15)
(31) (41) (24)
(113) (42)
(131) (51)
(311) (114)
(141)
(411)
(1113)
(1131)
(1311)
(3111)
MATHEMATICA
gappyQ[m_]:=And[m!={}, Union[m]!=Range[Min[m], Max[m]]];
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], gappyQ]], {n, 0, 15}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 03 2022
STATUS
approved