cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A079095 Squarefree numbers of the form (prime(k)+1)*(prime(k+1)+1)/4.

This page as a plain text file.
%I A079095 #19 Apr 07 2025 09:50:09
%S A079095 3,6,42,399,462,930,1054,3135,4830,6478,13110,19599,20022,24963,26394,
%T A079095 35530,38805,39999,41205,44310,52899,71002,74254,81510,94863,95790,
%U A079095 103362,109230,111547,114243,135790,144399,146685,157206,166866,183183
%N A079095 Squarefree numbers of the form (prime(k)+1)*(prime(k+1)+1)/4.
%H A079095 Reinhard Zumkeller, <a href="/A079095/b079095.txt">Table of n, a(n) for n = 1..10000</a>
%F A079095 A008966(a(n)) = 1.
%e A079095 (A000040(12)+1)*(A000040(12+1)+1)/4 = (37+1)*(41+1)/4 = 399 = 3*7*19, therefore 399 is a term.
%t A079095 With[{p = Prime[Range[150]]}, Select[(Most[p]+1) * (Rest[p]+1) / 4, SquareFreeQ]] (* _Amiram Eldar_, Apr 06 2025 *)
%o A079095 (Haskell)
%o A079095 a079095 n = a079095_list !! (n-1)
%o A079095 a079095_list = filter ((== 1) . a008966) a079079_list
%o A079095 -- _Reinhard Zumkeller_, Oct 09 2012
%Y A079095 Intersection of A005117 and A079079.
%Y A079095 Cf. A000040, A008966, A079093.
%K A079095 nonn
%O A079095 1,1
%A A079095 _Reinhard Zumkeller_, Dec 22 2002