cp's OEIS Frontend

A079704 a(n) = 2*prime(n)^2.

%I A079704 #35 Sep 08 2022 08:45:08
%S A079704 8,18,50,98,242,338,578,722,1058,1682,1922,2738,3362,3698,4418,5618,
%T A079704 6962,7442,8978,10082,10658,12482,13778,15842,18818,20402,21218,22898,
%U A079704 23762,25538,32258,34322,37538,38642,44402,45602,49298,53138,55778
%N A079704 a(n) = 2*prime(n)^2.
%C A079704 Numbers of the form 2*p^2 where p runs through the primes.
%C A079704 For these numbers m, there are precisely 5 groups of order m, hence this is a subsequence of A054397. If p = 2, these 5 groups of order 8 are described in example section of A054397, and when p is odd prime, the five corresponding groups are described in a comment of A143928. - _Bernard Schott_, Dec 11 2021
%D A079704 Pascal Ortiz, Exercices d'Algèbre, Collection CAPES / Agrégation, Ellipses, problème 1.35, pp. 70-74, 2004.
%H A079704 Reinhard Zumkeller, <a href="/A079704/b079704.txt">Table of n, a(n) for n = 1..1000</a>
%F A079704 a(n) = 2*A001248(n) = A100484(n)*A000040(n). - _Reinhard Zumkeller_, Nov 19 2013
%e A079704 a(2) = prime(2)^2*2 = 3^2*2 = 9*2 = 18.
%t A079704 2 Prime[Range[40]]^2 (* _Vincenzo Librandi_, Mar 27 2014 *)
%o A079704 (PARI) forprime (p=2,100,print1(p^2*2","))
%o A079704 (Haskell)
%o A079704 a079704 = (* 2) . a001248  -- _Reinhard Zumkeller_, Nov 19 2013
%o A079704 (Magma) [2*p^2: p in PrimesUpTo(200)]; // _Vincenzo Librandi_, Mar 27 2014
%o A079704 (Python)
%o A079704 from sympy import primerange
%o A079704 print([2*p**2 for p in primerange(1, 200)]) # _Michael S. Branicky_, Dec 11 2021
%Y A079704 Cf. A000040, A001248, A054397, A100484.
%Y A079704 A143928 is a subsequence.
%K A079704 easy,nonn
%O A079704 1,1
%A A079704 _Jon Perry_, Jan 31 2003
%E A079704 More terms from _Vincenzo Librandi_, Jan 29 2010
%E A079704 Offset corrected by _Reinhard Zumkeller_, Nov 19 2013