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 A258885 #42 Aug 04 2025 04:20:09 %S A258885 1550860550,44257207676,66072609790 %N A258885 Primitive weird numbers (A002975) having 6 distinct prime factors. %C A258885 a(4) <= 5976833582079328 = 2^5*181*197*353*431*34429 and a(5) <= 48083019473926272314825065088 = 2^7*257*97213*97973*100957*1520132521 that is certainly in this sequence. - _Giuseppe Melfi_, Oct 26 2015 %C A258885 a(4) <= 125258675788784 = 2^4 * 47 * 149 * 353 * 1307 * 2423. - _M. F. Hasler_, Jul 12 2016 %H A258885 G. Amato, M. F. Hasler, G. Melfi and M. Parton, <a href="https://hal.univ-antilles.fr/hal-01684543/">Primitive weird numbers having more than three distinct prime factors</a>, Riv. Mat. Univ. Parma, Vol. 7, No. 1 (2016) 153-163. %H A258885 G. 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, 147 (2015) 508-514; Lemma 2. %e A258885 a(1) = 1550860550 = 2 * 5^2 * 29 * 37 * 137 * 211 = A273815(1). (Abundance = 20) %e A258885 a(2) = 44257207676 = 2^2 * 11 * 37 * 59 * 523 * 881. (Abundance = 8, cf. A088833) %e A258885 a(3) = 66072609790 = 2 * 5 * 11 * 127^2 * 167 * 223 = A273815(3). (Abundance = 4, cf. A088832) %t A258885 (* copy the terms from A002975, assign them to 'lst' and then *) %t A258885 Select[ lst, PrimeNu@# == 6 &] %o A258885 (PARI) select(w->omega(w)==6, A002975) \\ Assuming that A002975 is defined as set or vector. - _M. F. Hasler_, Jul 12 2016 %Y A258885 Cf. A002975, A258401, A258882, A258883, A258884. %K A258885 nonn,bref,hard,more %O A258885 1,1 %A A258885 _Douglas E. Iannucci_ and _Robert G. Wilson v_, Jun 14 2015 %E A258885 One more term added and definition corrected by _Giuseppe Melfi_, Nov 02 2015