login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A324888 Minimal number of primorials (A002110) that add to A108951(n). 20

%I #9 Nov 18 2019 22:07:19

%S 1,1,1,2,1,2,1,2,2,2,1,4,1,2,6,4,1,4,1,4,6,2,1,4,6,2,2,4,1,6,1,2,6,2,

%T 10,8,1,2,6,2,1,2,1,4,6,2,1,4,8,12,6,4,1,4,6,8,6,2,1,6,1,2,6,4,14,12,

%U 1,4,6,10,1,6,1,2,10,4,18,12,1,4,8,2,1,4,12,2,6,8,1,12,18,4,6,2,8,8,1,16,12,8,1,12,1,8,8

%N Minimal number of primorials (A002110) that add to A108951(n).

%C Sum of digits when A108951(n) is written in primorial base (A049345).

%H Antti Karttunen, <a href="/A324888/b324888.txt">Table of n, a(n) for n = 1..30030</a>

%H <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>

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

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

%F a(n) = A276150(A108951(n)).

%F a(n) = A001222(A324886(n)).

%t With[{b = Reverse@ Prime@ Range@ 120}, Array[Total@ IntegerDigits[#, MixedRadix[b]] &@ Apply[Times, Map[#1^#2 & @@ # &, FactorInteger[#] /. {p_, e_} /; e > 0 :> {Times @@ Prime@ Range@ PrimePi@ p, e}]] &, 105] ] (* _Michael De Vlieger_, Nov 18 2019 *)

%o (PARI)

%o A034386(n) = prod(i=1, primepi(n), prime(i));

%o A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) }; \\ From A108951

%o A276150(n) = { my(s=0,m); forprime(p=2, , if(!n, return(s)); m = n%p; s += m; n = (n-m)/p); };

%o A324888(n) = A276150(A108951(n));

%Y Cf. A001222, A002110, A034386, A049345, A108951, A276086, A276150, A324886.

%Y Cf. A324383, A324386, A324387 (permutations of this sequence).

%K nonn

%O 1,4

%A _Antti Karttunen_, Mar 30 2019

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 18 11:52 EDT 2024. Contains 371779 sequences. (Running on oeis4.)