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A089040 Number of primitive partition identities with largest part n. 0
1, 5, 15, 47, 102, 276, 578, 1261, 2465, 5362, 9285, 18900, 33269, 58171, 99328, 181514, 287239, 502116, 775710, 1239710, 1956334, 3210736, 4660786, 7297823, 10997235, 16536803 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

REFERENCES

U.-U. Haus, M. Koeppe and R. Weismantel, A Primal All-Integer Algorithm Based on Irreducible Solutions, Math. Programming, Series B, 96 (2003), no. 2, 205-246

B. Sturmfels and R. R. Thomas, Variation of Cost Functions in Integer Programming, Mathematical Programming 77 (1997), 357-387

LINKS

Table of n, a(n) for n=2..27.

M. Koeppe, Primitive Partition Identities

EXAMPLE

a(3)=5 because we can write 2=1+1, 3=1+2, 3=1+1+1, 3+1=2+2, 3+3=2+2+2.

CROSSREFS

A007343 counts the homogeneous PPIs only, i.e. the same number of summands appears on the lhs and rhs.

Sequence in context: A197237 A307242 A296545 * A331237 A184262 A126944

Adjacent sequences:  A089037 A089038 A089039 * A089041 A089042 A089043

KEYWORD

nonn

AUTHOR

Matthias Koeppe (mkoeppe(AT)mail.math.uni-magdeburg.de), Dec 03 2003

STATUS

approved

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Last modified June 14 20:21 EDT 2021. Contains 345038 sequences. (Running on oeis4.)