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a(n) is the difference between the largest and smallest integer solutions to n=x/pi(x), where pi(x) = A000720(x).
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%I #22 Mar 27 2020 13:05:27

%S 6,6,24,30,126,35,64,774,180,0,600,221,770,2145,32,4573,8172,5852,

%T 5720,7035,792,7774,5256,2825,104,2484,1008,2088,8880,9176,10464,759,

%U 68,5880,23688,28490,3420,49686,58160,62074,136878,26316,264,130320,16882,705,96528,14063,95750

%N a(n) is the difference between the largest and smallest integer solutions to n=x/pi(x), where pi(x) = A000720(x).

%F a(n) = Max{x; n*pi(n)=x} - Min{x; n*pi(n)=x} = A038625(n) - A087235(n).

%F a(n) is divisible by n, the quotients are in A087237.

%e n=22: a(22) = 10246936436-10246935644 = 792 = 22*36.

%e a(2) = 6 since x/pi(x) = 2 for x = {2,4,6,8}; 8 - 2 = 6. - _Michael De Vlieger_, Mar 25 2017

%t Last@ # - First@ # & /@ Values@ Rest@ KeySort@ PositionIndex@ Table[n/PrimePi[n] /. k_ /; Not@ IntegerQ@ k -> 0, {n, 2, 10^6}] (* _Michael De Vlieger_, Mar 25 2017, Version 10 *)

%Y Cf. A038623-A038627, A057809, A087235-A087240.

%K nonn

%O 2,1

%A _Labos Elemer_, Sep 04 2003

%E a(27)-a(50) obtained from the values of A038625 computed by _Jan Büthe_. - _Giovanni Resta_, Sep 01 2018