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A121659
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Number of partitions of n into parts with at most one part not greater than 2.
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2
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1, 1, 1, 2, 3, 4, 5, 7, 9, 12, 15, 20, 25, 32, 40, 51, 63, 79, 97, 121, 148, 182, 221, 271, 328, 398, 479, 579, 694, 834, 995, 1190, 1415, 1684, 1995, 2366, 2793, 3298, 3881, 4569, 5360, 6288, 7355, 8603, 10037, 11705, 13619, 15842, 18388, 21333, 24703
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OFFSET
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1,4
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COMMENTS
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a(n) = A121081(n) - A008483(n-3) for n>2.
The number of partitions of n that have the first part at least thrice larger than the second part. Example: a(8) = #{8, 7+1, 6+2, 6+1+1, 5+1+1+1, 4+1+1+1+1, 3+1+1+1+1+1}=7. [From Mircea Merca, Jul 24 2011]
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LINKS
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Table of n, a(n) for n=1..51.
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EXAMPLE
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a(8) = #{8,7+1,6+2,5+3,4+4,4+3+1,3+3+2} = 7;
a(9) = #{9,8+1,7+2,6+3,5+4,5+3+1,4+4+1,4+3+2,3+3+3} = 9.
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CROSSREFS
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Cf. A027336.
Sequence in context: A003413 A100853 A174065 * A096814 A039861 A039877
Adjacent sequences: A121656 A121657 A121658 * A121660 A121661 A121662
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller, Aug 14 2006
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STATUS
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approved
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