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.
%I A113767 #30 Feb 16 2025 08:32:59 %S A113767 0,1,2,1,5,1,1,29,3,37,31,227,835,115,7615,6071,218431 %N A113767 Values of the exponents in A084435. %C A113767 If A084435 ever hits a Sierpinski number, the sequence is finite. %C A113767 a(18) > 10^6. - _Harsh R. Aggarwal_, Sep 14 2024 %H A113767 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SierpinskiNumberoftheSecondKind.html">Sierpinski Number of the Second Kind</a>. %o A113767 (PARI) a=2;for(x=1,16,for(k=0,1000000,p=2^k*a+1;if(isprime(p),print(k);break));a=p) %Y A113767 Cf. A084435, A113334, A121799. %K A113767 nonn,hard,more %O A113767 1,3 %A A113767 _Ken Takusagawa_, Jan 19 2006 %E A113767 a(16)-a(17) from _Harsh R. Aggarwal_, Apr 11 2018