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Cube excess of the n-th prime.
4

%I #11 Feb 15 2018 13:01:02

%S 1,2,4,6,3,5,9,11,15,2,4,10,14,16,20,26,32,34,3,7,9,15,19,25,33,37,39,

%T 43,45,49,2,6,12,14,24,26,32,38,42,48,54,56,66,68,72,74,86,7,11,13,17,

%U 23,25,35,41,47,53,55,61,65,67,77,91,95,97,101,115,121,4,6,10,16,24,30

%N Cube excess of the n-th prime.

%H Harvey P. Dale, <a href="/A104492/b104492.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A055400(A000040(n)).

%F a(n) = prime(n) - floor(prime(n)^(1/3))^3. - _Jon E. Schoenfield_, Jan 17 2015

%e a(48) = 7 because the 48th prime is 223 and 223 - 6^3 = 7, while 223 - 7^3 = -120.

%t lst={};Do[p=Prime[n];s=p^(1/3);f=Floor[s];a=f^3;d=p-a;AppendTo[lst,d],{n,6!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Mar 11 2009 *)

%t #-Floor[Surd[#,3]]^3&/@Prime[Range[80]] (* _Harvey P. Dale_, Feb 15 2018 *)

%Y Cf. A000040, A053186, A055400, A056892, A102821.

%K easy,nonn

%O 1,2

%A _Jonathan Vos Post_, Mar 10 2005