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A325679 Number of compositions of n such that every restriction to a circular subinterval has a different sum. 7
1, 1, 1, 3, 3, 5, 5, 13, 13, 27, 21, 41, 41, 77, 63, 143, 129, 241, 203, 385, 347 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
A composition of n is a finite sequence of positive integers summing to n.
A circular subinterval is a sequence of consecutive indices where the first and last indices are also considered consecutive.
LINKS
EXAMPLE
The a(1) = 1 through a(8) = 13 compositions:
(1) (2) (3) (4) (5) (6) (7) (8)
(12) (13) (14) (15) (16) (17)
(21) (31) (23) (24) (25) (26)
(32) (42) (34) (35)
(41) (51) (43) (53)
(52) (62)
(61) (71)
(124) (125)
(142) (152)
(214) (215)
(241) (251)
(412) (512)
(421) (521)
MATHEMATICA
suball[q_]:=Join[Take[q, #]&/@Select[Tuples[Range[Length[q]], 2], OrderedQ], Drop[q, #]&/@Select[Tuples[Range[2, Length[q]-1], 2], OrderedQ]];
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], UnsameQ@@Total/@suball[#]&]], {n, 0, 15}]
CROSSREFS
Sequence in context: A161220 A032022 A335357 * A147198 A147048 A110192
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, May 13 2019
STATUS
approved

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Last modified March 29 03:51 EDT 2024. Contains 371264 sequences. (Running on oeis4.)