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 A239546 Sum of the prime factors of n, where n runs through perfect numbers. 1
 5, 9, 33, 129, 8193, 131073, 524289, 2147483649, 2305843009213693953, 618970019642690137449562113, 162259276829213363391578010288129, 170141183460469231731687303715884105729 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA a(n) = A008472(A000396(n)). - Michel Marcus, Mar 21 2014 a(n) = A000668(n) + 2 (conjectured). - Michel Marcus, Mar 21 2014 EXAMPLE First perfect number is 6, its two prime factors are 2 and 3, so a(1) = 5. MATHEMATICA (* based on the code of Harvey P. Dale in A000396 *) perf=(# (#+1))/2&/@Select[2^Range[1000]-1, PrimeQ]; spf[n_]:=Total[First/@FactorInteger[n]]; spf/@perf (* Ivan N. Ianakiev, Jul 11 2015 *) CROSSREFS Cf. A000396, A008472. Sequence in context: A028351 A211952 A098640 * A083832 A070969 A200376 Adjacent sequences:  A239543 A239544 A239545 * A239547 A239548 A239549 KEYWORD nonn AUTHOR Madaline McCluskey, Mar 21 2014 EXTENSIONS Typo in data corrected by Michel Marcus, Mar 21 2014 STATUS approved

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Last modified October 19 16:17 EDT 2019. Contains 328223 sequences. (Running on oeis4.)