The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A075880 Position of the circles around (0,0) that contain record numbers of lattice points in the list of all circles around (0,0) that pass through lattice points, ordered by increasing radius. 3
 0, 1, 4, 13, 30, 121, 362, 1232, 1584, 7121, 17548, 32649, 37603, 174926, 437750, 821432, 1198677, 5678338, 14335447, 27044791, 43735981, 209473053, 531787054, 1006745669, 2097411347, 8474384496, 10122355701 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The first terms of this sequence were given by James Buddenhagen in a sci.math posting on May 05 2002 entitled "Circle with 3 lattice points" LINKS Table of n, a(n) for n=1..27. James Buddenhagen, Circle with 3 lattice points, thread in NG sci.math. Hugo Pfoertner, Asymptotic Behavior of A075880(n) FORMULA a(n) = k-1 for which A001481(k) = A071383(n). lim n ->infinity a(n) = k_LR * exp(n) / n^(1/2), where k_LR is the Landau-Ramanujan constant 0.764223653... (A064533) EXAMPLE a(4)=13 because A001481(14) = A071383(4)=25. CROSSREFS Cf. A001481, A064533, A071383, A230656. Sequence in context: A022913 A232228 A218213 * A042487 A154753 A335981 Adjacent sequences: A075877 A075878 A075879 * A075881 A075882 A075883 KEYWORD nonn AUTHOR Hugo Pfoertner, Oct 16 2002 EXTENSIONS Minor edits to adjust formula and example for changes to offset of related sequences by Ray Chandler, Jan 13 2012 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 6 03:16 EDT 2024. Contains 374957 sequences. (Running on oeis4.)