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%I #21 Nov 16 2022 11:50:00
%S 1,2,6,10,20,28,42,48,60,80,96,120,138,148,164,188,218,222,264,282,
%T 294,322,348,372,412,446,460,480,490,504,582,608,636,658,710,726,762,
%U 804,824,858,884,906,962,978,1004,1018,1086,1186,1206,1218,1238,1260,1282
%N a(n) = prime(prime(n)) - prime(n).
%H G. C. Greubel, <a href="/A168152/b168152.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A006450(n) - A000040(n).
%F a(n) ~ n (log n)^2. -_Charles R Greathouse IV_, May 25 2011
%p A168152 := proc(n) local p; p := ithprime(n) ; ithprime(p)-p ; end proc: seq(A168152(n),n=1..120) ; # _R. J. Mathar_, Nov 19 2009
%t Table[Prime[Prime[n]] - Prime[n], {n, 1, 100}] (* _G. C. Greubel_, Jul 14 2016 *)
%t Prime[#]-#&/@Prime[Range[100]] (* _Harvey P. Dale_, Nov 16 2022 *)
%o (Magma) [NthPrime(NthPrime(n))-NthPrime(n): n in [1..60]]; // _Vincenzo Librandi_, Jul 15 2016
%o (PARI) a(n) = my(p=prime(n)); prime(p) - p; \\ _Michel Marcus_, Mar 08 2022
%Y Cf. A000040, A006450.
%K nonn
%O 1,2
%A _Juri-Stepan Gerasimov_, Nov 19 2009
%E a(10) corrected by _R. J. Mathar_, Nov 19 2009
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