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A325680 Number of compositions of n such that every distinct circular subsequence has a different sum. 13

%I #13 Jun 19 2021 22:28:56

%S 1,1,2,4,5,6,8,14,16,29,24,42,46,78,66,146,133,242,208,386,352,620,

%T 494,948,842,1447

%N Number of compositions of n such that every distinct circular subsequence has a different sum.

%C A composition of n is a finite sequence of positive integers summing to n.

%C A circular subsequence is a sequence of consecutive terms where the first and last parts are also considered consecutive.

%e The a(1) = 1 through a(8) = 16 compositions:

%e (1) (2) (3) (4) (5) (6) (7) (8)

%e (11) (12) (13) (14) (15) (16) (17)

%e (21) (22) (23) (24) (25) (26)

%e (111) (31) (32) (33) (34) (35)

%e (1111) (41) (42) (43) (44)

%e (11111) (51) (52) (53)

%e (222) (61) (62)

%e (111111) (124) (71)

%e (142) (125)

%e (214) (152)

%e (241) (215)

%e (412) (251)

%e (421) (512)

%e (1111111) (521)

%e (2222)

%e (11111111)

%t subalt[q_]:=Union[ReplaceList[q,{___,s__,___}:>{s}],DeleteCases[ReplaceList[q,{t___,__,u___}:>{u,t}],{}]];

%t Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],UnsameQ@@Total/@subalt[#]&]],{n,0,15}]

%Y Cf. A000079, A008965, A108917, A143823, A169942, A276024.

%Y Cf. A325545, A325676, A325682, A325685, A325687, A325688.

%K nonn,more

%O 0,3

%A _Gus Wiseman_, May 13 2019

%E a(18)-a(25) from _Robert Price_, Jun 19 2021

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)