login
A294096
Sum of the differences of the larger and smaller parts in the partitions of n into two parts with the larger part prime and smaller part squarefree.
2
0, 0, 1, 2, 1, 4, 3, 8, 5, 4, 0, 12, 10, 20, 11, 16, 5, 28, 22, 38, 18, 28, 14, 48, 34, 32, 7, 24, 26, 56, 30, 64, 47, 68, 23, 60, 34, 68, 54, 58, 21, 112, 85, 144, 59, 104, 62, 168, 82, 124, 61, 110, 83, 180, 81, 124, 71, 152, 62, 202, 91, 192, 132, 224, 74
OFFSET
1,4
FORMULA
a(n) = Sum_{i=1..floor(n/2)} (n - 2i) * A008966(i) * A010051(n - i).
MATHEMATICA
Table[Sum[(n - 2 i) (PrimePi[n - i] - PrimePi[n - i - 1]) MoebiusMu[i]^2, {i, Floor[n/2]}], {n, 80}]
Table[Total[#[[1]]-#[[2]]&/@Select[IntegerPartitions[n, {2}], PrimeQ[#[[1]]]&&SquareFreeQ[ #[[2]]]&]], {n, 70}] (* Harvey P. Dale, Jun 08 2024 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Oct 22 2017
STATUS
approved