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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