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.

A074041 Product of first n single (i.e., non-twin) primes.

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%I A074041 #12 Nov 02 2021 11:35:49
%S A074041 2,46,1702,79994,4239682,284058694,22440636826,1862572856558,
%T A074041 165768984233662,16079591470665214,1816993836185169182,
%U A074041 230758217195516486114,30229326452612659680934,4746004253060187569906638,773598693248810573894781994
%N A074041 Product of first n single (i.e., non-twin) primes.
%C A074041 a(n) = 5*A002110(A049084(A074038(n)))/A074040(k), where k is the largest number such that A006512(k) < A007510(n).
%F A074041 a(1) = A007510(1) and a(n) = a(n-1)*A007510(n) for n > 1.
%e A074041 The first four single primes are 2, 23, 37 and 47, therefore a(4) = 2*23*37*47 = 79994.
%t A074041 nn=50;tps=Union[Flatten[Select[Partition[Prime[Range[nn]],2,1],Last[#]- First[#] ==2&]]]; ntps=Complement[Prime[Range[nn]],tps];Rest[ FoldList[ Times,1,ntps]]  (* _Harvey P. Dale_, Mar 31 2011 *)
%K A074041 nonn
%O A074041 1,1
%A A074041 _Reinhard Zumkeller_, Aug 13 2002
%E A074041 More terms from _Harvey P. Dale_, Mar 31 2011