login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A304102 a(n) = Product_{d|n, d<n} prime(A304101(d)-1). 7

%I

%S 1,2,2,4,2,8,2,12,4,8,2,120,2,12,8,24,2,200,2,120,12,12,2,1680,4,8,20,

%T 180,2,2000,2,120,12,44,12,12600,2,44,8,1680,2,1200,2,180,200,20,2,

%U 42000,6,440,44,120,2,7800,12,3960,44,12,2,3234000,2,44,120,840,8,10200,2,264,20,3000,2,630000,2,20,440,1452,18,2000,2,109200,260,44,2,1386000

%N a(n) = Product_{d|n, d<n} prime(A304101(d)-1).

%H Antti Karttunen, <a href="/A304102/b304102.txt">Table of n, a(n) for n = 1..4181</a>

%F a(n) = Product_{d|n, d<n} A000040(A304101(d)-1).

%F a(n) = 2*A304104(n) / A000040(A304101(n)-1).

%F Other identities. For all n >= 1:

%F A001222(a(n)) = A032741(n).

%F A007814(a(n)) = A293435(n).

%F A007949(a(n)) = A304095(n).

%o (PARI)

%o \\ Needs also code from A304101:

%o A304102(n) = { my(m=1); fordiv(n,d,if(d<n, m *= prime(A304101(d)-1))); (m); };

%Y Cf. A304101, A304103 (restricted growth sequence transform of this sequence), A304104.

%K nonn

%O 1,2

%A _Antti Karttunen_, May 13 2018

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 23 22:38 EDT 2019. Contains 325278 sequences. (Running on oeis4.)