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.

A153138 Smallest sequence of odd primes such that no sum of at least two terms is prime.

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%I A153138 #12 Jul 22 2025 06:16:40
%S A153138 3,5,7,83,317,383,29567,423509,118661483,52542428123
%N A153138 Smallest sequence of odd primes such that no sum of at least two terms is prime.
%o A153138 (PARI) a=[]; for(n=1, 10, forprime(p=if(a,a[#a]+2,3), , setsearch(a, p)&&next; for(i=1, 2^#a-1, isprime(normlp(vecextract(a, i), 1)+p)&&next(2)); a=concat(a, p); print1(p", "))) \\ Very simplistic, should at least avoid an odd number of terms in the partial sum of earlier terms. \\ _M. F. Hasler_, Jan 29 2015
%Y A153138 Cf. A153136, A153137, A133660, A052349, A254337, A254341.
%K A153138 more,nonn
%O A153138 1,1
%A A153138 _Benoit Jubin_, Dec 19 2008
%E A153138 a(8)-a(10) from _Donovan Johnson_, Dec 23 2008