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.

A334214 Odd numbers m such that m^k + 1 is squarefree for all 0 <= k <= (m - 1)/2.

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%I A334214 #20 Apr 25 2020 02:29:17
%S A334214 1,5,9,13,21,25,85,105,165
%N A334214 Odd numbers m such that m^k + 1 is squarefree for all 0 <= k <= (m - 1)/2.
%C A334214 a(10) > 10000, if it exists. Most of the relevant factorizations of 165^k+1 were already present in the FactorDB database. The factorization of 165^79+1 has been completed with the software CADO-NFS. - _Giovanni Resta_, Apr 22 2020
%o A334214 (PARI) isOK(m) = k=0; until(k>(m-1)/2, if(!issquarefree(m^k+1), return(0)); k++); 1;
%o A334214 for(m=0, 140, if(isOK(m)&&m%2==1, print1(m, ", ")))
%Y A334214 Cf. A334212, A334213.
%K A334214 nonn,more,hard
%O A334214 1,2
%A A334214 _Gionata Neri_, Apr 18 2020
%E A334214 a(9) from _Giovanni Resta_, Apr 22 2020