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A328402
Number of terms of A048103 found in range A002110(n-1) .. A002110(n)-1.
2
1, 3, 17, 130, 1517, 20013, 346902, 6634497, 154067794
OFFSET
1,2
COMMENTS
Number of integers from A002110(n-1) to A002110(n)-1 that are in range of A276086.
a(n) is the total number of times n occurs in A328404.
FORMULA
a(n) <= A061720(n-1) for all n >= 1.
MATHEMATICA
With[{s = FoldList[Times, 1, Prime@ Range@ 7]}, Array[Boole[# == 2] + Count[Range[s[[# - 1]], s[[#]] - 1], _?(Times @@ Boole@ Map[First@ # > Last@ # &, FactorInteger@ #] > 0 &)] &, Length@ s - 1, 2]] (* Michael De Vlieger, Oct 17 2019 *)
PROG
(PARI)
A002110(n) = prod(i=1, n, prime(i));
isA048103(n) = { my(f = factor(n)); for(k=1, #f~, if(f[k, 2]>=f[k, 1], return(0))); (1); };
A328402(n) = sum(k=A002110(n-1), A002110(n)-1, isA048103(k));
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Antti Karttunen, Oct 17 2019
STATUS
approved