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A335583
Number of 1's in the partitions of n into 4 parts.
0
0, 0, 0, 0, 4, 3, 5, 6, 8, 9, 12, 13, 16, 18, 21, 23, 27, 29, 33, 36, 40, 43, 48, 51, 56, 60, 65, 69, 75, 79, 85, 90, 96, 101, 108, 113, 120, 126, 133, 139, 147, 153, 161, 168, 176, 183, 192, 199, 208, 216, 225, 233, 243, 251, 261, 270, 280, 289, 300, 309, 320, 330, 341
OFFSET
0,5
FORMULA
a(n) = Sum_{k=1..floor(n/4)} Sum_{j=k..floor((n-k)/3)} Sum_{i=j..floor((n-j-k)/2)} [k = 1] + [j = 1] + [i = 1] + [n-i-j-k = 1], where [ ] is the Iverson bracket.
MATHEMATICA
Table[Sum[Sum[Sum[KroneckerDelta[k, 1] + KroneckerDelta[j, 1] + KroneckerDelta[i, 1] + KroneckerDelta[n - i - j - k, 1], {i, j, Floor[(n - j - k)/2]}], {j, k, Floor[(n - k)/3]}], {k, Floor[n/4]}], {n, 0, 80}]
CROSSREFS
Sequence in context: A296413 A016701 A023829 * A328109 A000211 A059902
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Jan 26 2021
STATUS
approved