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A328834
Square root of the prime factor form (A276086) of the primorial base expansion, computed for such numbers for which it is a square.
3
1, 3, 5, 15, 25, 75, 7, 21, 35, 105, 175, 525, 49, 147, 245, 735, 1225, 3675, 343, 1029, 1715, 5145, 8575, 25725, 11, 33, 55, 165, 275, 825, 77, 231, 385, 1155, 1925, 5775, 539, 1617, 2695, 8085, 13475, 40425, 3773, 11319, 18865, 56595, 94325, 282975, 121, 363, 605, 1815, 3025, 9075, 847, 2541, 4235, 12705, 21175, 63525, 5929, 17787
OFFSET
1,2
COMMENTS
All terms are odd.
FORMULA
MATHEMATICA
With[{b = MixedRadix[Reverse@ Prime@ Range@ 20]}, Select[Array[Sqrt@ Function[k, Times @@ Power @@@ # &@ Transpose@ {Prime@ Range@ Length@ k, Reverse@ k}]@ IntegerDigits[#, b] &, 10^3, 0], IntegerQ]] (* Michael De Vlieger, Oct 30 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 30 2019
STATUS
approved