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A238480 Number of partitions p of n that include (min(p) + max(p))/2 as a part. 4

%I #6 Feb 27 2014 20:22:47

%S 1,2,2,3,2,5,3,6,8,9,10,20,18,25,38,43,53,77,87,114,150,176,220,290,

%T 343,422,535,641,783,978,1164,1415,1733,2068,2497,3026,3595,4304,5174,

%U 6140,7300,8709,10283,12176,14435,16978,20001,23579,27640,32423,38024

%N Number of partitions p of n that include (min(p) + max(p))/2 as a part.

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

%e a(6) counts these partitions:

%e 6 (as (6+6)/2 = 6 is included),

%e 33 (as (3+3)/2 = 3 is included),

%e 321 (as (3+1)/2 = 2 is included),

%e 222 (as (2+2)/2 = 2 is included),

%e 111111 (as (1+1)/2 = 1 is included).

%e Thus a(6) = 5.

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

%Y Cf. A238481.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Feb 27 2014

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Last modified May 7 21:53 EDT 2024. Contains 372317 sequences. (Running on oeis4.)