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 A275493 #16 Sep 02 2023 07:56:58 %S A275493 0,0,0,0,0,0,0,1,1,1,2,2,3,6,8,9,10,14,16,20,24,29,33,46,55,61,79,87, %T A275493 103,128,152,173,234,266,313,403,483,561,756,850,940 %N A275493 Number of primitive weird numbers (A002975) below 2^n. %C A275493 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 A275493 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 A275493 (PARI) vector(40,n,#select(t->t<2^n,A002975)) \\ assuming that A002975 is defined as a set, vector or list with enough terms. %Y A275493 Cf. A002975, A006037, A258333, A258882, A275494, A275491, A275492. %K A275493 nonn,more %O A275493 0,11 %A A275493 _M. F. Hasler_, Jul 30 2016 %E A275493 a(0) inserted, a(39) corrected, and a(40) added by _Amiram Eldar_, Sep 02 2023