A364350 Number of strict integer partitions of n such that no part can be written as a nonnegative linear combination of the others.
1, 1, 1, 1, 1, 2, 1, 3, 2, 3, 3, 5, 3, 6, 5, 7, 6, 9, 7, 11, 10, 14, 12, 16, 15, 20, 17, 24, 22, 27, 29, 32, 30, 41, 36, 49, 45, 50, 52, 65, 63, 70, 77, 80, 83, 104, 98, 107, 116, 126, 134, 152, 148, 162, 180, 196, 195, 227, 227, 238, 272, 271, 293, 333, 325
Offset: 0
Keywords
Examples
The a(16) = 6 through a(22) = 12 strict partitions: (16) (17) (18) (19) (20) (21) (22) (9,7) (9,8) (10,8) (10,9) (11,9) (12,9) (13,9) (10,6) (10,7) (11,7) (11,8) (12,8) (13,8) (14,8) (11,5) (11,6) (13,5) (12,7) (13,7) (15,6) (15,7) (13,3) (12,5) (14,4) (13,6) (14,6) (16,5) (16,6) (7,5,4) (13,4) (7,6,5) (14,5) (17,3) (17,4) (17,5) (14,3) (8,7,3) (15,4) (8,7,5) (19,2) (18,4) (15,2) (16,3) (9,6,5) (11,10) (19,3) (7,6,4) (17,2) (9,7,4) (8,7,6) (12,10) (8,6,5) (11,5,4) (9,7,5) (9,7,6) (9,6,4) (10,7,4) (9,8,5) (10,8,3) (7,6,5,4) (11,6,4) (11,7,3)
Crossrefs
Programs
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Mathematica
combs[n_,y_]:=With[{s=Table[{k,i},{k,y},{i,0,Floor[n/k]}]},Select[Tuples[s],Total[Times@@@#]==n&]]; Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&And@@Table[combs[#[[k]],Delete[#,k]]=={},{k,Length[#]}]&]],{n,0,15}]
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Python
from sympy.utilities.iterables import partitions def A364350(n): if n <= 1: return 1 alist, c = [set(tuple(sorted(set(p))) for p in partitions(i)) for i in range(n)], 1 for p in partitions(n,k=n-1): if max(p.values(),default=0)==1: s = set(p) if not any(set(t).issubset(s-{q}) for q in s for t in alist[q]): c += 1 return c # Chai Wah Wu, Sep 23 2023
Extensions
More terms and offset corrected by Martin Fuller, Sep 11 2023
Comments