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 A154896 #5 Mar 30 2012 17:33:59 %S A154896 3,23,487,8115,33550311,8589869023,137438691291,2305843008139952067, %T A154896 2658455991569831744654692615953842055, %U A154896 191561942608236107294793378084303638130997321548169039 %N A154896 Sum of proper divisors minus the number of proper divisors of the perfect number A000396(n). %C A154896 a(n) is also the difference between the n-th perfect number and its number of proper divisors. %F A154896 a(n) = A152770(A000396(n)) = A000396(n)-A133033(n). %e A154896 a(2) is 23 because the second perfect number is 28 and the sum of proper divisors of 28 is also 28 = 1+2+4+7+14 and the number of proper divisors of 28 is 5, then 28-5 = 23. %Y A154896 Cf. A000396, A001065, A032741, A133033, A152770. %K A154896 nonn %O A154896 1,1 %A A154896 _Omar E. Pol_, Jan 25 2009 %E A154896 More terms from _Max Alekseyev_, Dec 12 2011