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 A096821 #5 Nov 07 2016 14:34:49 %S A096821 24,304,127744,33501184,8589082624, %T A096821 10384593717069654320312270165377024, %U A096821 822752278660603021077484591278411581166520461101278617407586304,15177100720513508366558296147058741458142670970377727126573378340391656803557965824 %N A096821 Solutions to Mod[sigma(x),x]=12 of the form p*(p+13)/2 where p is a prime of form=2^j-13, of which j exponents are listed in A096818. %C A096821 The relevant A084306 includes additional solution like 21, while A076496 contains solutions of 6k form too. %H A096821 F. Firoozbakht, M. F. Hasler, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL13/Hasler/hasler2.html">Variations on Euclid's formula for Perfect Numbers</a>, JIS 13 (2010) #10.3.1. %e A096821 8th term is (2^136)*(-13+2^137) with 83 decimal digits; n=4: a[4]=(2^3)*(16-13)=24; %Y A096821 Cf. A084306, A096518, A000203, A076496. %K A096821 nonn %O A096821 1,1 %A A096821 _Labos Elemer_, Jul 13 2004