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!)
A110378 a(n) = Sum_{prime p <= n} n!/p!. 1

%I #7 Sep 03 2017 03:30:54

%S 1,4,16,81,486,3403,27224,245016,2450160,26951761,323421132,

%T 4204474717,58862646038,882939690570,14127035049120,240159595835041,

%U 4322872725030738,82134581775584023,1642691635511680460

%N a(n) = Sum_{prime p <= n} n!/p!.

%e a(6) = 6!(2! + 1/3! + 1/5!) = 486.

%p a:=proc(n) local s, i: s:=0: for i from 2 to n do if isprime(i)=true then s:=s+1/i! else s:=s: fi: od: n!*s: end: seq(a(n),n=2..23); # _Emeric Deutsch_, Jul 24 2005

%Y Cf. A038048, A110373, A110374, A110376, A110377.

%K easy,nonn

%O 2,2

%A _Amarnath Murthy_, Jul 24 2005

%E Corrected and extended by _Emeric Deutsch_, Jul 24 2005

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 August 11 06:35 EDT 2024. Contains 375059 sequences. (Running on oeis4.)