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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

%I #11 Nov 01 2019 18:39:33

%S 1,3,5,15,25,75,7,21,35,105,175,525,49,147,245,735,1225,3675,343,1029,

%T 1715,5145,8575,25725,11,33,55,165,275,825,77,231,385,1155,1925,5775,

%U 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

%N Square root of the prime factor form (A276086) of the primorial base expansion, computed for such numbers for which it is a square.

%C All terms are odd.

%H Antti Karttunen, <a href="/A328834/b328834.txt">Table of n, a(n) for n = 1..9072</a>

%H <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>

%F a(n) = A276086(A328770(n)) = A000196(A276086(A328849(n))).

%t 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 *)

%Y Cf. A000196, A276086, A328849, A328770.

%K nonn

%O 1,2

%A _Antti Karttunen_, Oct 30 2019

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Last modified August 9 19:29 EDT 2024. Contains 375044 sequences. (Running on oeis4.)