This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A328406 The length of primorial base expansion (number of significant digits) of A276086(A276086(A276086(n))), where A276086(n) converts primorial base expansion of n into its prime product form. 7

%I

%S 2,3,2,3,3,7,4,5,6,3,7,8,12,8,7,12,12,7,17,11,25,21,24,84,49,63,94,67,

%T 49,97,4,6,8,9,7,10,6,14,13,4,14,11,22,22,19,20,66,16,23,40,20,19,50,

%U 105,81,87,104,71,49,81,12,10,34,21,9,16,11,23,16,17,85,49,71,27,44,21,93,87,39,58,171,50,205,112,54,78,78

%N The length of primorial base expansion (number of significant digits) of A276086(A276086(A276086(n))), where A276086(n) converts primorial base expansion of n into its prime product form.

%H Antti Karttunen, <a href="/A328406/b328406.txt">Table of n, a(n) for n = 0..32768</a>

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

%F a(n) = A235224(A328403(n)) = A328404(A276087(n)) = A328405(A276086(n)).

%F For all n, A000040(a(n)) > A328398(n).

%t Block[{b = MixedRadix[Reverse@ Prime@ Range@ 120], f}, f[n_] := Times @@ Power @@@ # &@ Transpose@ {Prime@ Range@ Length@ #, Reverse@ #} &@ IntegerDigits[n, b]; Array[IntegerLength[Nest[f, #, 3], b] &, 87, 0]] (* _Michael De Vlieger_, Oct 17 2019 *)

%o (PARI)

%o A235224(n) = { my(s=0, p=2); while(n, s++; n = n\p; p = nextprime(1+p)); (s); };

%o A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };

%o A328403(n) = A276086(A276086(A276086(n)));

%o A328406(n) = A235224(A328403(n));

%Y Cf. A235224, A276086, A276087, A328398, A328403, A328404, A328405.

%K nonn

%O 0,1

%A _Antti Karttunen_, Oct 16 2019

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 9 03:27 EST 2019. Contains 329872 sequences. (Running on oeis4.)