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 A110431 Average of positive multiples of 3 with n decimal digits, rounded down. 1
 6, 55, 550, 5500, 55000, 550000, 5500000, 55000000, 550000000, 5500000000, 55000000000, 550000000000, 5500000000000, 55000000000000, 550000000000000, 5500000000000000, 55000000000000000, 550000000000000000, 5500000000000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Subsidiary sequence: Average of positive multiples of k with n decimal digits, rounded down. LINKS FORMULA For n > 1, a(n+1) = 10 * a(n). EXAMPLE a(2) = average {12,15,...96,99} = floor((12+99)/2) = 55. PROG (PARI) a(n)=(11*10^(n-1)+1)\2 CROSSREFS Cf. A110430. Sequence in context: A342388 A253475 A215853 * A121661 A118836 A079589 Adjacent sequences: A110428 A110429 A110430 * A110432 A110433 A110434 KEYWORD nonn,base AUTHOR Amarnath Murthy, Aug 02 2005 EXTENSIONS Corrected and extended by Joshua Zucker, May 10 2006 Formula and program from Charles R Greathouse IV, Aug 03 2010 STATUS approved

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Last modified March 23 23:09 EDT 2023. Contains 361454 sequences. (Running on oeis4.)