[go: up one dir, main page]

login
A240214
Number of partitions p of n such that median(p) = multiplicity(min(p)).
5
0, 1, 0, 0, 1, 0, 0, 1, 3, 4, 5, 5, 8, 9, 13, 15, 21, 24, 36, 41, 57, 71, 90, 108, 142, 167, 210, 254, 315, 373, 466, 552, 682, 810, 985, 1173, 1429, 1683, 2030, 2404, 2882, 3390, 4049, 4755, 5651, 6630, 7827, 9157, 10798, 12593, 14788, 17224, 20154, 23420
OFFSET
0,9
FORMULA
a(n) = A240213(n) - A240212(n) for n >= 0.
a(n) + A240212(n) + A240215(n) = A000041(n) for n >= 0.
EXAMPLE
a(6) counts these 3 partitions: 422, 3311, 22211.
MATHEMATICA
z = 40; f[n_] := f[n] = IntegerPartitions[n]; t1 = Table[Count[f[n], p_ /; Median[p] < Count[p, Min[p]]], {n, 0, z}] (* A240212 *)
t2 = Table[Count[f[n], p_ /; Median[p] <= Count[p, Min[p]]], {n, 0, z}] (* A240213 *)
t3 = Table[Count[f[n], p_ /; Median[p] == Count[p, Min[p]]], {n, 0, z}] (* A240214 *)
t4 = Table[Count[f[n], p_ /; Median[p] > Count[p, Min[p]]], {n, 0, z}] (* A240215 *)
t5 = Table[Count[f[n], p_ /; Median[p] >= Count[p, Min[p]]], {n, 0, z}] (* A240216 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Apr 04 2014
STATUS
approved