cp's OEIS Frontend

A324581 a(n) = A276086(A002182(n)).

%I A324581 #16 Mar 29 2019 19:08:10
%S A324581 2,3,9,5,25,625,35,875,49,2401,117649,77,184877,456533,14641,1771561,
%T A324581 214358881,143,20449,2924207,418161601,8550986578849,
%U A324581 174859124550883201,3575694237941010577249,23298085122481,1599034490244763,32698656291015158587,30466726698629,39841104144361,52099905419549,89093921102069,152355876914189,260537564663909
%N A324581 a(n) = A276086(A002182(n)).
%C A324581 Note that gcd(a(n), A002182(n)) = A324198(A002182(n)) = 1 for all n because each term of A002182 is a product of primorial numbers (A002110).
%H A324581 Antti Karttunen, <a href="/A324581/b324581.txt">Table of n, a(n) for n = 1..670</a>
%H A324581 Michael De Vlieger, <a href="/A324581/a324581.png">Small chart of first terms</a>.
%H A324581 Michael De Vlieger, <a href="/A324581/a324581_1.png">2400 x 3600 chart of first terms</a>.
%H A324581 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A324581 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%F A324581 a(n) = A276086(A002182(n)).
%F A324581 a(n) = A324582(n)/A002182(n).
%F A324581 A001221(a(n)) = A324381(n).
%F A324581 A001222(a(n)) = A324382(n).
%t A324581 Block[{b = MixedRadix[Reverse@ Prime@ Range@ 20], s = DivisorSigma[0, Range[10^5]], t}, t = Map[FirstPosition[s, #][[1]] &, Union@ FoldList[Max, s]]; Array[Times @@ Power @@@ # &@ Transpose@ {Prime@ Range@ Length@ #, Reverse@ #} &@ IntegerDigits[(*a002182[[#]]*)t[[#]], b] &, Length@ t]] (* _Michael De Vlieger_, Mar 18 2019 *)
%o A324581 (PARI)
%o A324581 \\ A002182 assumed to be precomputed
%o A324581 A276086(n) = { my(i=0,m=1,pr=1,nextpr); while((n>0),i=i+1; nextpr = prime(i)*pr; if((n%nextpr),m*=(prime(i)^((n%nextpr)/pr));n-=(n%nextpr));pr=nextpr); m; };
%o A324581 A324581(n) = A276086(A002182(n));
%Y A324581 Subsequence of A324576.
%Y A324581 Cf. A002110, A002182, A276086, A324198, A324381, A324382, A324582.
%K A324581 nonn
%O A324581 1,1
%A A324581 _Antti Karttunen_, Mar 09 2019