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A019987
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Decimal expansion of tangent of 89 degrees.
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12
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5, 7, 2, 8, 9, 9, 6, 1, 6, 3, 0, 7, 5, 9, 4, 2, 4, 6, 8, 7, 2, 7, 8, 1, 4, 7, 5, 3, 7, 1, 1, 2, 5, 7, 7, 9, 8, 0, 2, 1, 7, 5, 2, 2, 2, 3, 5, 1, 4, 3, 9, 2, 6, 4, 7, 2, 5, 8, 1, 1, 0, 3, 6, 0, 6, 5, 2, 9, 2, 2, 8, 9, 3, 6, 4, 7, 9, 1, 9, 3, 0, 6, 7, 2, 4, 1, 6, 2, 8, 2, 2, 0, 6, 8, 3, 8, 8, 0, 6
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OFFSET
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2,1
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COMMENTS
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The least k > 0 such that floor(cot(1°)*10^k) is prime is k = 39. - M. F. Hasler, May 19 2023
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LINKS
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Mohammad K. Azarian, Forty-Five Nested Equilateral Triangles and cosecant of 1 degree, Problem 813, College Mathematics Journal, Vol. 36, No. 5, November 2005, p. 413-414; Solution, College Mathematics Journal, Vol. 37, No. 5, November 2006, pp. 394-395.
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FORMULA
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Equals (Sum_{k=1..90} 2*k*sin(2*k)) / 90, with k in degrees (link USAMO 1996). - Bernard Schott, Apr 30 2022
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EXAMPLE
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57.28996...
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MAPLE
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MATHEMATICA
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First[RealDigits[Cot[Pi/180], 10, 100]] (* Paolo Xausa, Apr 23 2024 *)
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PROG
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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