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 A038760 a(n) = n - floor(sqrt(n)) * ceiling(sqrt(n)). 5
 0, 0, 0, 1, 0, -1, 0, 1, 2, 0, -2, -1, 0, 1, 2, 3, 0, -3, -2, -1, 0, 1, 2, 3, 4, 0, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 0, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 0, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 0, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, -8, -7, -6, -5, -4 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,9 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..10000 FORMULA a(n) = n - A000196(n)*A003059(n) = n - A038759(n). EXAMPLE Sqrt(31) is between 5 and 6, and 31 - 6*5 = 1, so a(31)=1. MAPLE a:= n-> n -(x-> floor(x)*ceil(x))(sqrt(n)): seq(a(n), n=0..100);  # Alois P. Heinz, Jan 03 2015 MATHEMATICA f[n_]:=n-Floor[Sqrt[n]]*Ceiling[Sqrt[n]]; Table[f[n], {n, 0, 5!}] (* Vladimir Joseph Stephan Orlovsky, Mar 29 2010 *) PROG (PARI) a(n)=if(issquare(n), 0, my(s=sqrtint(n)); n-s^2-s) \\ Charles R Greathouse IV, Feb 07 2013 CROSSREFS Cf. A053188. Sequence in context: A036580 A101674 A100820 * A245825 A143946 A226860 Adjacent sequences:  A038757 A038758 A038759 * A038761 A038762 A038763 KEYWORD sign,easy AUTHOR Henry Bottomley, May 03 2000 STATUS approved

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Last modified September 17 10:37 EDT 2019. Contains 327129 sequences. (Running on oeis4.)