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 A239546 #26 Aug 28 2015 18:02:07 %S A239546 5,9,33,129,8193,131073,524289,2147483649,2305843009213693953, %T A239546 618970019642690137449562113,162259276829213363391578010288129, %U A239546 170141183460469231731687303715884105729 %N A239546 Sum of the prime factors of n, where n runs through perfect numbers. %F A239546 a(n) = A008472(A000396(n)). - _Michel Marcus_, Mar 21 2014 %F A239546 a(n) = A000668(n) + 2 (conjectured). - _Michel Marcus_, Mar 21 2014 %e A239546 First perfect number is 6, its two prime factors are 2 and 3, so a(1) = 5. %t A239546 (* based on the code of _Harvey P. Dale_ in A000396 *) %t A239546 perf=(# (#+1))/2&/@Select[2^Range[1000]-1,PrimeQ]; %t A239546 spf[n_]:=Total[First/@FactorInteger[n]];spf/@perf (* _Ivan N. Ianakiev_, Jul 11 2015 *) %Y A239546 Cf. A000396, A008472. %K A239546 nonn %O A239546 1,1 %A A239546 _Madaline McCluskey_, Mar 21 2014 %E A239546 Typo in data corrected by _Michel Marcus_, Mar 21 2014