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 A230294 a(n) = Sum_{i=1..n} d(4*i+1) - Sum_{i=1..n} d(2*i+1), where d(n) = A000005(n). 4
 0, 1, 1, 0, 2, 3, 1, 3, 3, 1, 5, 5, 3, 5, 5, 5, 5, 5, 5, 8, 10, 6, 8, 7, 5, 11, 9, 7, 11, 12, 10, 10, 12, 10, 12, 14, 10, 12, 12, 11, 17, 16, 14, 16, 14, 14, 18, 18, 14, 16, 18, 14, 16, 18, 18, 25, 23, 19, 19, 18, 20, 20, 22, 20, 24, 24, 18, 24, 24, 22, 26, 25, 21, 27, 29, 27, 27, 27, 25, 25, 29, 25, 29, 28, 26, 32 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS a(n) = A230476(n) - A230293(n). - Jonathan Sondow, Oct 20 2013 LINKS Jorge Luis Cimadevilla Villacorta, Certain inequalities associated with the divisor function, Amer. Math. Monthly, 120 (2013), 832-837. (Shows that a(n) >= 0.) MAPLE See A230290. PROG (PARI) vector(100, n, sum(i=1, n, numdiv(4*i+1)) - sum(i=1, n, numdiv(2*i+1))) \\ Michel Marcus, Oct 09 2014 CROSSREFS Cf. A000005, A230290-A230296, A230476. Sequence in context: A289171 A231633 A039702 * A104483 A080717 A239214 Adjacent sequences:  A230291 A230292 A230293 * A230295 A230296 A230297 KEYWORD nonn AUTHOR N. J. A. Sloane, Oct 17 2013 STATUS approved

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Last modified May 31 00:06 EDT 2020. Contains 334747 sequences. (Running on oeis4.)