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A239881

Number of strict partitions of n having an ordering in which no parts of equal parity are juxtaposed.

1, 1, 1, 2, 1, 3, 2, 5, 3, 7, 6, 10, 9, 13, 15, 18, 22, 23, 33, 31, 46, 41, 65, 55, 87, 73, 117, 99, 153, 132, 199, 177, 254, 236, 324, 313, 408, 412, 512, 540, 639, 701, 795, 904, 986, 1159, 1221, 1473, 1509, 1861, 1862, 2336, 2298, 2915, 2830, 3615, 3485

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OFFSET

0,4

COMMENTS

A strict partition is one in which every part has multiplicity 1.

a(n) = Sum_{k=-1..1} A240021(n,k). - Alois P. Heinz, Apr 02 2014

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

EXAMPLE

a(12) counts these 9 partitions: [12], [9,2,1], [3,8,1], [7,4,1], [7,2,3], [5,6,1], [6,3,2,1], [5,4,3], [5,4,1,2].

MATHEMATICA

d[n_] := Select[IntegerPartitions[n], Max[Length /@ Split@#] == 1 &];