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A325390
Heinz number of the negated differences plus one of the integer partition with Heinz number n (with the last part taken to be 0).
16
1, 3, 5, 6, 7, 9, 11, 12, 10, 15, 13, 18, 17, 21, 15, 24, 19, 18, 23, 30, 25, 33, 29, 36, 14, 39, 20, 42, 31, 27, 37, 48, 35, 51, 21, 36, 41, 57, 55, 60, 43, 45, 47, 66, 30, 69, 53, 72, 22, 30, 65, 78, 59, 36, 35, 84, 85, 87, 61, 54, 67, 93, 50, 96, 49, 63, 71
OFFSET
1,2
COMMENTS
The Heinz number of a positive integer sequence (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
The differences of a sequence are defined as if the sequence were increasing, so for example the differences of (6,3,1) (with the last part taken to be 0) are (-3,-2,-1).
EXAMPLE
The Heinz number of (6,3,1) is 130, and its negated differences plus one are (4,3,2), which has Heinz number 105, so a(130) = 105.
MATHEMATICA
primeptn[n_]:=If[n==1, {}, Reverse[Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]];
Table[Times@@Prime/@(1-Differences[Append[primeptn[n], 0]]), {n, 100}]
CROSSREFS
Number of appearances of n is A325392(n).
Positions of squarefree numbers are A325367.
Sequence in context: A247523 A169957 A165712 * A296365 A291166 A333228
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 02 2019
STATUS
approved