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.

A291446 Squarefree triprimes of the form p*q*r such that p + q + r + 1 is prime.

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%I A291446 #10 Aug 29 2017 21:52:53
%S A291446 30,42,66,78,102,110,138,182,186,222,230,246,266,282,290,318,366,374,
%T A291446 402,434,438,498,506,518,530,582,590,602,606,618,638,642,710,782,786,
%U A291446 806,854,890,906,942,962,1002,1010,1022,1034,1038,1106,1118,1146,1158,1166,1178,1298
%N A291446 Squarefree triprimes of the form p*q*r such that p + q + r + 1 is prime.
%C A291446 All terms are even. - _Muniru A Asiru_, Aug 29 2017
%H A291446 Charles R Greathouse IV, <a href="/A291446/b291446.txt">Table of n, a(n) for n = 1..10000</a>
%e A291446 42 = 2*3*7 and 2 + 3 + 7 + 1 is prime, so 42 is a term.
%e A291446 402 = 2*3*67 and 2 + 3 + 67 + 1 is prime, so 402 is a term.
%t A291446 With[{nnn=80}, Take[Times@@@Select[Subsets[Prime[Range[nnn]], {3}], PrimeQ[Total[#] + 1] &]//Union, nnn]]
%o A291446 (GAP)
%o A291446 A291446:=List(Filtered(Filtered(List(Filtered(List([1..10^6],Factors),i->Length(i)=3),Set),j->Length(j)=3),i->IsPrime(Sum(i)+1)),Product); # _Muniru A Asiru_, Aug 29 2017
%o A291446 (PARI) list(lim)=my(v=List()); forprime(p=5, lim\6, forprime(q=3, min(lim\(2*p),p-2), if(isprime(p+q+3), listput(v, 2*p*q)))); Set(v) \\ _Charles R Greathouse IV_, Aug 29 2017
%Y A291446 Subsequence of A075819, and hence of A007304.
%Y A291446 Cf. A291319.
%K A291446 nonn
%O A291446 1,1
%A A291446 _Vincenzo Librandi_, Aug 24 2017