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 A069289 Sum of odd divisors of n <= sqrt(n). 11
 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 4, 6, 1, 4, 1, 1, 9, 1, 1, 4, 1, 6, 4, 1, 1, 4, 6, 1, 4, 1, 1, 9, 1, 1, 4, 8, 6, 4, 1, 1, 4, 6, 8, 4, 1, 1, 9, 1, 1, 11, 1, 6, 4, 1, 1, 4, 13, 1, 4, 1, 1, 9, 1, 8, 4, 1, 6, 13, 1, 1, 11, 6, 1, 4, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,9 COMMENTS a(n) = Sum{d : d = A182469(n,k), d <= A000196(n), k=1..A001227(n)}. - Reinhard Zumkeller, Apr 05 2015 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA G.f.: Sum_{k>=1} (2*k - 1) * x^((2*k - 1)^2) / (1 - x^(2*k - 1)). - Ilya Gutkovskiy, Apr 04 2020 MATHEMATICA Table[Total[Select[Divisors[n], OddQ[#]&&#<=Sqrt[n]&]], {n, 120}] (* Harvey P. Dale, Jul 16 2017 *) PROG (PARI) a(n) = my(ir = sqrtint(n)); sumdiv(n, d, (d % 2) * (d <= ir) * d); \\ Michel Marcus, Jan 14 2014 (Haskell) a069289 n = sum \$ takeWhile (<= a000196 n) \$ a182469_row n -- Reinhard Zumkeller, Apr 05 2015 CROSSREFS Cf. A000593, A000203, A069288. Cf. A000196, A182469, A001227. Sequence in context: A316584 A146325 A333807 * A341309 A346778 A097322 Adjacent sequences:  A069286 A069287 A069288 * A069290 A069291 A069292 KEYWORD nonn AUTHOR Reinhard Zumkeller, Mar 14 2002 STATUS approved

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Last modified November 28 04:13 EST 2021. Contains 349400 sequences. (Running on oeis4.)