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A238481 Number of partitions p of n that do not include (min(p) + max(p))/2 as a part. 3

%I #11 Feb 27 2014 20:23:07

%S 0,0,1,2,5,6,12,16,22,33,46,57,83,110,138,188,244,308,403,513,642,826,

%T 1035,1285,1615,2014,2475,3077,3782,4626,5678,6934,8410,10242,12386,

%U 14951,18042,21711,26011,31198,37283,44465,52978,62999,74699,88580,104753

%N Number of partitions p of n that do not include (min(p) + max(p))/2 as a part.

%F A238480(n) + A238481(n) = A000041(n).

%e a(6) counts these partitions:

%e 51 (as part (5+1)/2 = 3 is not included),

%e 42 (as (4+2)/2 = 3 is not included),

%e 411 (as (4+1)/2 = 2.5 cannot be included),

%e 3111 (as (3+1)/2 = 2 is not included),

%e 2211 (as (2+1)/2 = 1.5 cannot be included),

%e 21111 (ditto).

%e Thus a(6) = 6.

%t Table[Count[IntegerPartitions[n], p_ /; !MemberQ[p, (Min[p] + Max[p])/2]], {n, 40}]

%Y Cf. A238480.

%K nonn,easy

%O 1,4

%A _Clark Kimberling_, Feb 27 2014

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Last modified April 25 07:07 EDT 2024. Contains 371964 sequences. (Running on oeis4.)