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 A000709 Related to population of numbers of form x^2 + y^2. (Formerly M1060 N0398) 1
 1, 2, 4, 7, 12, 21, 38, 68, 124, 229, 428, 806, 1530, 2919, 5591, 10750, 20730, 40077, 77653, 150752, 293161, 570963, 1113524, 2174315, 4250367, 8317036, 16289636, 31931697, 62642861, 122980015, 241595101, 474910732, 934088141, 1838227618, 3619356631 (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 Alois P. Heinz, Table of n, a(n) for n = 1..1000 Daniel Shanks, The second-order term in the asymptotic expansion of B(x), Mathematics of Computation 18 (1964), pp. 75-86. FORMULA a(n) = int (1/sqrt(log(u)), u=1..2^(n-1))))). - Based on Alois P. Heinz's Maple program, Alonso del Arte, Oct 24 2014 MAPLE Digits := 500: a:= n-> `if`(n=1, 1, round(evalf(int(1/sqrt(ln(u)), u=1..2^(n-1))))): seq(a(n), n=1..35); # Alois P. Heinz, Dec 26 2010 MATHEMATICA Table[Floor[Integrate[1/Sqrt[Log[u]], {u, 1, 2^(n - 1)}]], {n, 2, 40}] (* Based on Alois P. Heinz's Maple program, Alonso del Arte, Oct 24 2014 *) CROSSREFS Sequence in context: A307058 A307060 A218600 * A054161 A023433 A190168 Adjacent sequences:  A000706 A000707 A000708 * A000710 A000711 A000712 KEYWORD nonn AUTHOR EXTENSIONS a(17) corrected and more terms from Alois P. Heinz, Dec 26 2010 STATUS approved

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Last modified June 1 19:32 EDT 2020. Contains 334762 sequences. (Running on oeis4.)