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.

A228198 Smallest of five consecutive primes whose sum is not a prime.

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%I A228198 #15 Sep 08 2022 08:46:05
%S A228198 2,3,17,23,37,41,47,61,71,83,89,97,101,103,131,139,167,173,181,193,
%T A228198 197,199,227,233,239,241,251,257,271,277,281,283,293,313,317,331,337,
%U A228198 347,367,373,389,397,421,431,439,457,463,487,491,499,503,509,547,563,587,593
%N A228198 Smallest of five consecutive primes whose sum is not a prime.
%H A228198 Vincenzo Librandi, <a href="/A228198/b228198.txt">Table of n, a(n) for n = 1..1000</a>
%e A228198 47 is in the sequence because 47+53+59+61+67 = 287 and 287 is not a prime.
%t A228198 Transpose[Select[Partition[Prime[Range[150]], 5, 1], ! PrimeQ[Total[#]] &]][[1]]
%t A228198 Prime[Select[Range[150], ! PrimeQ[Sum[Prime[# + i], {i, 0, 4}]] &]] (* _Bruno Berselli_, Aug 21 2013 *)
%o A228198 (Magma) [NthPrime(n): n in [1..120] | not IsPrime(&+[NthPrime(n+s): s in [0..4]])];
%Y A228198 Cf. A000040, A152468.
%K A228198 nonn
%O A228198 1,1
%A A228198 _Vincenzo Librandi_, Aug 20 2013