A280289 Numbers n such that number of partitions of n is odd and number of partitions of n into distinct parts is even.
3, 4, 6, 13, 14, 16, 17, 18, 20, 23, 24, 29, 32, 33, 36, 37, 38, 39, 41, 43, 44, 48, 49, 52, 53, 54, 56, 60, 61, 63, 67, 68, 69, 71, 72, 73, 76, 81, 82, 83, 85, 87, 88, 89, 90, 91, 93, 95, 99, 102, 104, 105, 107, 111, 114, 115, 118, 119, 121, 123, 127, 132, 134, 138, 139, 140, 143, 144, 146, 148, 150, 152, 156, 157, 159
Offset: 1
Examples
6 is in the sequence because we have: ---------------------------------- number of partitions = 11 (is odd) ---------------------------------- 6 = 6 5 + 1 = 6 4 + 2 = 6 4 + 1 + 1 = 6 3 + 3 = 6 3 + 2 + 1 = 6 3 + 1 + 1 + 1 = 6 2 + 2 + 2 = 6 2 + 2 + 1 + 1 = 6 2 + 1 + 1 + 1 + 1 = 6 1 + 1 + 1 + 1 + 1 + 1 = 6 ------------------------------------------------------ number of partitions into distinct parts = 4 (is even) ------------------------------------------------------ 6 = 6 5 + 1 = 6 4 + 2 = 6 3 + 2 + 1 = 6
Links
- Eric Weisstein's World of Mathematics, Partition Function P, Partition Function Q
- Index entries for related partition-counting sequences
Programs
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Mathematica
Select[Range[160], Mod[PartitionsP[#1], 2] == 1 && Mod[PartitionsQ[#1], 2] == 0 & ]
Comments