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 A335830 Decimal expansion of the sum of the reciprocals of the multiply-perfect numbers. 1
 1, 2, 1, 4, 4, 0, 7, 6, 0, 8, 5, 9, 1, 4, 2, 7, 1, 9, 2, 9, 0, 6, 3, 8, 6, 3, 7, 3, 9, 0, 8, 2, 1, 8, 5, 6, 7, 8, 2, 2, 2, 7, 0, 6, 3, 1, 2, 8, 3, 4, 0, 8, 9, 0, 1, 1, 8, 6, 5, 6, 3, 9, 6, 2, 4, 2, 3, 9, 9, 3, 3, 9, 0, 1, 7, 8, 4, 4, 8, 4, 1, 6, 8, 0, 7, 8, 8, 8, 0, 0, 0, 8, 8, 8, 8, 6, 1, 9, 2, 9 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The first 18 terms were calculated by Bayless and Kinlaw (2015). LINKS Jonathan Bayless and Paul Kinlaw, On repeated values of sigma and multiperfect numbers, Journal of Combinatorics and Number Theory, Vol. 7, No. 3 (2015), pp. 177-189. FORMULA Equals Sum_{k>=1} 1/A007691(k). EXAMPLE 1.21440760859142719... MATHEMATICA multiPerfects = Cases[Import["https://oeis.org/A007691/b007691.txt", "Table"], {_, _}][[;; , 2]]; RealDigits[Total[1/multiPerfects], 10, 18][[1]] CROSSREFS Cf. A007691, A335118. Sequence in context: A009477 A324658 A105568 * A004175 A136756 A214670 Adjacent sequences:  A335827 A335828 A335829 * A335831 A335832 A335833 KEYWORD nonn,cons AUTHOR Amiram Eldar, Jun 25 2020 EXTENSIONS More terms (computed using the b-file at A007691) from Jon E. Schoenfield, Jan 25 2021 STATUS approved

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Last modified September 28 04:53 EDT 2021. Contains 347703 sequences. (Running on oeis4.)