|
%I #27 Sep 08 2022 08:45:54
%S 3,6,9,15,18,24,27,33,42,45,54,60,63,69,78,87,90,99,105,108,117,123,
%T 132,144,150,153,159,162,168,189,195,204,207,222,225,234,243,249,258,
%U 267,270,285,288,294,297,315,333,339,342,348,357,360,375,384,393,402,405
%N a(n) = 3/2 * (prime(n)-1).
%H G. C. Greubel, <a href="/A179893/b179893.txt">Table of n, a(n) for n = 2..1000</a>
%F A179545 / prime(n).
%F a(n) = 3*A005097(n-1). - _R. J. Mathar_, Aug 15 2010
%e For n=4, the fourth prime is 7, so a(4) = (3/2) * (7 - 1) = 9. Note that since the sequence starts at n=2, prime(n) is odd, so a(n) is an integer. - _Michael B. Porter_, Jul 19 2016
%t Table[(3/2)*(Prime[n] - 1), {n,2,100}] (* _G. C. Greubel_, Jun 17 2016 *)
%o (PARI) a(n)=prime(n)\2*3 \\ _Charles R Greathouse IV_, May 19 2011
%o (Magma) 3/2*(NthPrime(n)-1): n in [2..60]]; // _Vincenzo Librandi_, Jun 18 2016
%Y Cf. A000040, A179545.
%K easy,nonn
%O 2,1
%A _Odimar Fabeny_, Jul 30 2010, Aug 02 2010
%E More terms from _R. J. Mathar_, Aug 15 2010
|
