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 A128285 #9 Jan 09 2021 19:25:43 %S A128285 1365,4305,10465,11685,15873,27105,31845,35245,50065,54033,58765, %T A128285 74965,84513,91977,95557,95613,96033,104377,113997,114405,117957, %U A128285 118105,126357,127605,136437,170905,197985,209605,215373,226185,248385,277797 %N A128285 Numbers of the form m = p1 * p2 * p3 * p4 where for each d|m we have (d+m/d)/2 prime and p1 < p2 < p3 < p4 each prime. %H A128285 David A. Corneth, <a href="/A128285/b128285.txt">Table of n, a(n) for n = 1..3114</a> %e A128285 1365=3 * 5 * 7 * 13 and (3 * 5 * 7 * 13+1)/2, (3+5 * 7 * 13)/2, (5+3 * 7 * 13)/2, (7+3 * 5 * 13)/2, (13+3 * 5 * 7)/2, (3 * 5+7.13)/2, (3 * 7+5 * 13)/2, (3 * 13+5 * 7)/2 are all primes and 1365 is the smallest such integer which is the product of 4 primes, so 1365 is in the sequence. %Y A128285 Cf. A128281, A005383, A128283, A128284, A128286. %Y A128285 Subsequence of A046390. %K A128285 nonn %O A128285 1,1 %A A128285 Kok Seng Chua (chuakokseng(AT)hotmail.com), Mar 05 2007 %E A128285 New name from _David A. Corneth_, Jan 09 2021