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 A247334 #17 Oct 15 2014 23:38:19
%S A247334 1,2,3,4,6,8,10,16
%N A247334 Highly abundant numbers which are not abundant.
%C A247334 A number n is called "abundant" if sigma(n) > 2n, and "highly abundant" if sigma(n) > sigma(m) for all m < n. With these definitions, it's possible for a number to be highly abundant but not abundant. (A similar situation occurs with 2 being prime and highly composite.)
%C A247334 Fischer shows that all highly abundant numbers greater than 20 are multiples of 6. Since 6 is perfect and multiples of perfect numbers are abundant, this list is finite and complete.
%H A247334 Daniel Fischer, <a href="http://math.stackexchange.com/questions/466401/prove-that-if-f-n-is-highly-abundant-then-so-is-n/469199#469199">Prove that if Fn is highly abundant, then so is n</a>, Mathematics Stack Exchange, Aug 13 2013
%e A247334 10 is in the sequence because sigma(10) > sigma(m) for m = 1 to 9, yet sigma(10) = 17 < 20.
%o A247334 (PARI) for(n=1, 1000, if((sum(i=1, n-1, sign(sigma(n)-sigma(i))) == n-1) && (sigma(n) <= 2*n), print1(n, ", "))) \\ _Michel Marcus_, Sep 21 2014
%o A247334 (PARI) is_A247334(n)={!for(i=2,n-1, sigma(n)>sigma(i)||return) && sigma(n)<=2*n} \\ _M. F. Hasler_, Oct 15 2014
%Y A247334 Members of A002093 not in A005101. Members of A002093 in (A000396 union A005100).
%K A247334 fini,full,nonn
%O A247334 1,2
%A A247334 _Andrew Rodland_, Sep 13 2014