login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A284608
Number of partitions of n such that the (sum of distinct odd parts) = floor(n/2).
2
0, 1, 2, 0, 0, 1, 2, 5, 6, 1, 3, 8, 9, 1, 5, 20, 20, 28, 45, 30, 29, 43, 69, 60, 51, 119, 174, 86, 75, 213, 307, 355, 375, 416, 583, 517, 541, 663, 923, 1198, 1291, 1205, 1650, 2156, 2365, 1803, 2469, 4196, 4596, 4637, 6073, 6684, 7374, 6740, 8829, 12345
OFFSET
1,3
EXAMPLE
a(8) counts these 5 partitions: 431, 3311, 3221, 32111, 311111.
MATHEMATICA
Table[p = IntegerPartitions[n]; Length[Select[Table[Total[Select[DeleteDuplicates[p[[k]]], OddQ]], {k, Length[p]}], # == Floor[n/2] &]], {n, 60}] (* Peter J. C. Moses, Mar 29 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Mar 30 2017
STATUS
approved