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 A000099 Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record. (Formerly M1374 N0534) 6
 1, 2, 5, 10, 20, 24, 26, 41, 53, 130, 149, 205, 234, 287, 340, 410, 425, 480, 586, 840, 850, 986, 1680, 1843, 2260, 2591, 3023, 3024, 3400, 3959, 3960, 5182, 5183, 7920, 9796, 11233, 14883, 15119, 15120, 19593, 21600, 21603, 21604, 22177, 28559, 28560 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS David W. Wilson, Table of n, a(n) for n = 1..200 W. C. Mitchell, The number of lattice points in a k-dimensional hypersphere, Math. Comp., 20 (1966), 300-310. MATHEMATICA nmax = 3*10^4; A[n_] := 1 + 4*Floor[Sqrt[n]] + 4*Floor[Sqrt[n/2]]^2 + 8* Sum[Floor[Sqrt[n - j^2]], {j, Floor[Sqrt[n/2]]+1, Floor[Sqrt[n]]}]; V[n_] := Pi*n; P[n_] := A[n] - V[n]; record = 0; A000099 = Reap[For[k = 0; n = 1, n <= nmax, n++, p = Abs[P[n]]; If[p > record, record = p; k++; Sow[n]; Print["a(", k, ") = ", n]; ]]][[2, 1]] (* Jean-François Alcover, Feb 03 2016 *) CROSSREFS Cf. A000323, A000036, A000092, A000413, A000223. Sequence in context: A016029 A018327 A285571 * A039690 A243938 A365630 Adjacent sequences: A000096 A000097 A000098 * A000100 A000101 A000102 KEYWORD nonn AUTHOR N. J. A. Sloane EXTENSIONS Entry revised by N. J. A. Sloane, Jun 26 2005 STATUS approved

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Last modified September 22 08:46 EDT 2023. Contains 365519 sequences. (Running on oeis4.)