OFFSET
1,10
COMMENTS
The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
EXAMPLE
The partition with Heinz number 7865 is (6,5,5,3), which has the following diagram. The 3 X 4 rectangle is shown in dots.
. . . o o o
. . . o o
. . . o o
. . .
The size of the complement is 7, so a(7865) = 7.
MATHEMATICA
Table[If[n==1, 0, With[{q=Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]}, Total[q]-q[[1]]*Length[q]]], {n, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Dec 27 2022
STATUS
approved