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A090852
a(n) is the least positive integer such that the integer part of the arithmetic-geometric mean of a(n) and 1 is equal to n.
10
1, 4, 7, 10, 13, 16, 20, 24, 27, 31, 35, 39, 43, 47, 51, 55, 60, 64, 68, 73, 77, 81, 86, 90, 95, 100, 104, 109, 113, 118, 123, 127, 132, 137, 142, 146, 151, 156, 161, 166, 171, 176, 181, 186, 191, 196, 201, 206, 211, 216, 221, 226, 231, 236, 241, 246, 251, 256, 262
OFFSET
1,2
LINKS
FORMULA
floor( agm(a(n), 1) ) = n, for n>=1.
MATHEMATICA
Table[Ceiling[y /. FindRoot[Pi/(2*EllipticK[1 - y^2]) == n, {y, 2*n}]], {n, 1, 60}] (* Vaclav Kotesovec, Sep 28 2019 *)
CROSSREFS
Sequence in context: A310681 A143456 A310682 * A182112 A090955 A310683
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Dec 10 2003
STATUS
approved