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 A276663 Sum of primes dividing n-th perfect number (with repetition). 0
 5, 11, 39, 139, 8215, 131103, 524323, 2147483707, 2305843009213694071, 618970019642690137449562287, 162259276829213363391578010288339, 170141183460469231731687303715884105979 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers that are equal to the sum of the prime factors (A001414) of some perfect number. The next term is too large to include. A001222(a(n)) is 1, 1, 2, 1, 3, 4, 2, 2, 4, 6, 7, 1, 11, ... LINKS FORMULA a(n) = 2^A000043(n) + 2*A000043(n) - 3. a(n) = A001414(A000396(n)). - Michel Marcus, Sep 18 2016 EXAMPLE 39 is in this sequence because 39 - 2^(5 - 1) = 31 = 2^5 - 1 and 31 is prime. MATHEMATICA Table[Total[Times@@@FactorInteger[PerfectNumber[n]]], {n, 15}] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 22 2019 *) PROG (PARI) \\ Ochem & Rao: no odd perfect numbers below 10^1500 forprime(p=2, 2281, if(ispseudoprime(t=2^p-1), print1(2^p+2*p-3", "))) \\ Charles R Greathouse IV, Sep 18 2016 CROSSREFS Subsequence of A131898. Supersequence of A276511. Cf. A000043, A000396, A001222, A001414, A007013, A192436, A239546, A276493. Sequence in context: A197337 A302766 A212199 * A187984 A063626 A154297 Adjacent sequences:  A276660 A276661 A276662 * A276664 A276665 A276666 KEYWORD nonn,easy AUTHOR Juri-Stepan Gerasimov, Sep 12 2016 STATUS approved

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Last modified November 26 04:03 EST 2022. Contains 358353 sequences. (Running on oeis4.)