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 A136363 a(n) = Sum_{ composite k, 1 <= k <= 10^n} (Sum of divisors d of k with 1 < d < k). 1
 23, 3150, 321582, 32241015, 3224590836, 322466618438, 32246696794797, 3224670272194238, 322467032612360629, 32246703337400266401, 3224670334173560419030, 322467033423857340138979 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA a(n) = A072692(n) - 10^n*(10^n+3)/2 + 1 [From Max Alekseyev, May 10 2009] EXAMPLE a(1)=23 because the divisors through 10^1 are as follows: 4 (2); 6 (2,3); 8 (2,4); 9 (3); 10 (2,5). The sum is 2+2+3+2+4+3+2+5=23. CROSSREFS Cf. A136364. Sequence in context: A030461 A152521 A267692 * A290786 A248335 A222031 Adjacent sequences:  A136360 A136361 A136362 * A136364 A136365 A136366 KEYWORD easy,nonn AUTHOR Enoch Haga, Dec 26 2007, Dec 29 2007 EXTENSIONS Edited by N. J. A. Sloane, Jan 12 2008 Extended by Max Alekseyev, May 10 2009 STATUS approved

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Last modified May 26 14:39 EDT 2020. Contains 334626 sequences. (Running on oeis4.)