A238625 Number of partitions p of n such that 1 + (1/2)*max(p) is a part of p.
0, 1, 1, 2, 2, 3, 4, 5, 6, 9, 11, 14, 19, 24, 31, 41, 51, 65, 84, 105, 132, 167, 207, 257, 321, 395, 486, 599, 731, 892, 1089, 1319, 1597, 1933, 2327, 2798, 3361, 4021, 4805, 5736, 6825, 8109, 9625, 11393, 13469, 15905, 18738, 22049, 25915, 30401, 35620
Offset: 1
Examples
a(6) counts these partitions: 222, 2211, 21111.
Links
- Giovanni Resta, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Table[Count[IntegerPartitions[n], p_ /; MemberQ[p, 1 + Max[p]/2]], {n, 50}] p[n_, m_] := If[m > n, 0, If[n == m, 1, p[n, m] = Sum[p[n - m, j], {j, m}]]]; a[1] = 0; a[n_] := 1 + Sum[p[n-k-1, 2*k], {k, n/2}]; Array[a,100] (* Giovanni Resta, Mar 07 2014 *)