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LCM of all divisors of d of n such that d+1 is a prime power.
3

%I #14 Aug 17 2013 02:12:45

%S 1,2,3,4,1,6,7,8,3,10,1,12,1,14,15,16,1,18,1,20,21,22,1,24,1,26,3,28,

%T 1,30,31,16,3,2,7,36,1,2,3,40,1,42,1,44,15,46,1,48,7,10,3,52,1,18,1,

%U 56,3,58,1,60,1,62,63,16,1,66,1,4,3,70,1,72,1,2,15,4,7,78,1,80,3,82,1,84,1

%N LCM of all divisors of d of n such that d+1 is a prime power.

%C a(A185208(n)) = 1. - _Reinhard Zumkeller_, Nov 01 2012

%H Reinhard Zumkeller, <a href="/A049073/b049073.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>

%t a[n_] := LCM @@ Select[Divisors[n], PrimeNu[# + 1] == 1 &]; Table[a[n], {n, 1, 85}] (* _Jean-François Alcover_, Aug 17 2013 *)

%o (Haskell)

%o a049073 = foldl lcm 1 . filter ((== 1) . a010055 . (+ 1)) . a027750_row

%o -- _Reinhard Zumkeller_, Nov 01 2012

%Y Cf. A141197, A027750, A010055.

%K nonn,easy,nice

%O 1,2

%A David E. Daykin

%E More terms from _Erich Friedman_, Jun 03 2001