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 A275492 #16 Sep 02 2023 04:15:44 %S A275492 0,1,1,5,6,11,24,37,67,124,223,382 %N A275492 Number of primitive weird numbers (A002975) between 10^n and 10^(n+1). %C A275492 It is not known unconditionally whether there are infinitely many primitive weird numbers (PWN, A002975), although numerical data provides strong evidence: even the number of weird numbers of the form 2^k*p*q (A258882, A258333) seems to increase rapidly as k increases. Melfi has shown that Cramer's conjecture implies the infiniteness of PWN. %H A275492 Giuseppe Melfi, <a href="http://dx.doi.org/10.1016/j.jnt.2014.07.024">On the conditional infiniteness of primitive weird numbers</a>, Journal of Number Theory, Volume 147, February 2015, Pages 508-514. %o A275492 (PARI) a(n)=sum(n=10^n\2+1,5*10^n,is_A002975(n*2)) %Y A275492 Cf. A002975, A006037, A258333, A258882, A275491, A275493, A275494. %K A275492 nonn,more %O A275492 0,4 %A A275492 _M. F. Hasler_, Jul 30 2016 %E A275492 Wrong initial term removed and a(11) added by _Amiram Eldar_, Sep 02 2023