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 A276663 #36 Oct 21 2024 04:36:29
%S A276663 5,11,39,139,8215,131103,524323,2147483707,2305843009213694071,
%T A276663 618970019642690137449562287,162259276829213363391578010288339,
%U A276663 170141183460469231731687303715884105979
%N A276663 Sum of primes dividing n-th perfect number (with repetition).
%C A276663 Numbers that are equal to the sum of the prime factors (A001414) of some perfect number.
%C A276663 The next term is too large to include.
%C A276663 A001222(a(n)) is 1, 1, 2, 1, 3, 4, 2, 2, 4, 6, 7, 1, 11, ...
%H A276663 Amiram Eldar, <a href="/A276663/b276663.txt">Table of n, a(n) for n = 1..18</a>
%F A276663 a(n) = 2^A000043(n) + 2*A000043(n) - 3, assuming that there are no odd perfect numbers.
%F A276663 a(n) = A001414(A000396(n)). - _Michel Marcus_, Sep 18 2016
%e A276663 39 is in this sequence because 39 - 2^(5 - 1) = 31 = 2^5 - 1 and 31 is prime.
%t A276663 Table[Total[Times@@@FactorInteger[PerfectNumber[n]]],{n,15}] (* _Harvey P. Dale_, Sep 22 2019 *)
%o A276663 (PARI) \\ Ochem & Rao: no odd perfect numbers below 10^1500
%o A276663 forprime(p=2,2281, if(ispseudoprime(t=2^p-1), print1(2^p+2*p-3", "))) \\ _Charles R Greathouse IV_, Sep 18 2016
%Y A276663 Subsequence of A131898. Supersequence of A276511.
%Y A276663 Cf. A000043, A000396, A001222, A001414, A007013, A192436, A239546, A276493.
%K A276663 nonn
%O A276663 1,1
%A A276663 _Juri-Stepan Gerasimov_, Sep 12 2016