%I A110376
%S A110376 1,2,9,32,250,864,12348,67584,804816,5760000,116915040,686776320,
%T A110376 19323757440,157991178240,2951575200000,42301705420800,1202482800691200,
%U A110376 10048607738265600,425162773111910400,4541227794432000000
%N A110376 SUM (n!/r) where r is relatively prime to n and less than n.
%e A110376 a(6) = 6!{1/1 +1/5}=864.
%p A110376 a:=proc(n) local s,r: s:=0: for r from 1 to n do if gcd(r,n)=1 then s:=s+1/
r else s:=s: fi: od: n!*s end: seq(a(n),n=1..23); (Deutsch)
%t A110376 Do[Print[n! * Plus @@ Map[(1/#)&, Select[Range[n], GCD[ #, n] == 1 &]]],
{n, 1, 30}] (Propper)
%Y A110376 Cf. A110373, A110374, A038048.
%Y A110376 Sequence in context: A150920 A013501 A114853 this_sequence A036505 A056916
A139628
%Y A110376 Adjacent sequences: A110373 A110374 A110375 this_sequence A110377 A110378
A110379
%K A110376 easy,nonn
%O A110376 1,2
%A A110376 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jul 24 2005
%E A110376 More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Ryan Propper
(rpropper(AT)stanford.edu) and Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com),
Jul 25 2005
|