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Sum of the odd parts in the partitions of n into 5 parts.
0

%I #9 Sep 14 2019 16:50:40

%S 0,0,0,0,0,5,4,10,12,27,32,62,76,132,158,244,290,425,504,698,824,1107,

%T 1292,1679,1948,2476,2842,3527,4034,4941,5610,6751,7626,9064,10180,

%U 11978,13384,15595,17350,20020,22186,25420,28054,31909,35094,39689,43486

%N Sum of the odd parts in the partitions of n into 5 parts.

%H <a href="/index/Par#part">Index entries for sequences related to partitions</a>

%F a(n) = Sum_{l=1..floor(n/5)} Sum_{k=l..floor((n-1)/4)} Sum_{j=k..floor((n-k-l)/3)} Sum_{i=j..floor((n-j-k-l)/2)} (i * (i mod 2) + j * (j mod 2) + k * (k mod 2) + l * (l mod 2) + (n-i-j-k-l) * ((n-i-j-k-l) mod 2)).

%e The partitions of n into 5 parts for n = 10, 11, ..

%e 1+1+1+1+10

%e 1+1+1+2+9

%e 1+1+1+3+8

%e 1+1+1+4+7

%e 1+1+1+5+6

%e 1+1+1+1+9 1+1+2+2+8

%e 1+1+1+2+8 1+1+2+3+7

%e 1+1+1+3+7 1+1+2+4+6

%e 1+1+1+4+6 1+1+2+5+5

%e 1+1+1+5+5 1+1+3+3+6

%e 1+1+1+1+8 1+1+2+2+7 1+1+3+4+5

%e 1+1+1+2+7 1+1+2+3+6 1+1+4+4+4

%e 1+1+1+3+6 1+1+2+4+5 1+2+2+2+7

%e 1+1+1+1+7 1+1+1+4+5 1+1+3+3+5 1+2+2+3+6

%e 1+1+1+2+6 1+1+2+2+6 1+1+3+4+4 1+2+2+4+5

%e 1+1+1+3+5 1+1+2+3+5 1+2+2+2+6 1+2+3+3+5

%e 1+1+1+1+6 1+1+1+4+4 1+1+2+4+4 1+2+2+3+5 1+2+3+4+4

%e 1+1+1+2+5 1+1+2+2+5 1+1+3+3+4 1+2+2+4+4 1+3+3+3+4

%e 1+1+1+3+4 1+1+2+3+4 1+2+2+2+5 1+2+3+3+4 2+2+2+2+6

%e 1+1+2+2+4 1+1+3+3+3 1+2+2+3+4 1+3+3+3+3 2+2+2+3+5

%e 1+1+2+3+3 1+2+2+2+4 1+2+3+3+3 2+2+2+2+5 2+2+2+4+4

%e 1+2+2+2+3 1+2+2+3+3 2+2+2+2+4 2+2+2+3+4 2+2+3+3+4

%e 2+2+2+2+2 2+2+2+2+3 2+2+2+3+3 2+2+3+3+3 2+3+3+3+3

%e --------------------------------------------------------------------------

%e n | 10 11 12 13 14 ...

%e --------------------------------------------------------------------------

%e a(n) | 32 62 76 132 158 ...

%e --------------------------------------------------------------------------

%e - _Wesley Ivan Hurt_, Sep 12 2019

%t Table[Sum[Sum[Sum[Sum[i * Mod[i, 2] + j * Mod[j, 2] + k * Mod[k, 2] + l * Mod[l, 2] + (n - i - j - k - l) * Mod[n - i - j - k - l, 2], {i, j, Floor[(n - j - k - l)/2]}], {j, k, Floor[(n - k - l)/3]}], {k, l, Floor[(n - l)/4]}], {l, Floor[n/5]}], {n, 0, 50}]

%K nonn

%O 0,6

%A _Wesley Ivan Hurt_, Aug 06 2019