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A087478

Decimal expansion of (sqrt(20467) - sqrt(19578) + sqrt(10177) - sqrt(9553))/2.

3, 1, 4, 1, 5, 9, 2, 6, 5, 1, 8, 3, 2, 9, 0, 0, 5, 6, 2, 8, 7, 8, 6, 7, 4, 4, 8, 2, 8, 8, 3, 4, 3, 3, 3, 7, 1, 6, 7, 7, 5, 1, 1, 5, 3, 3, 4, 0, 2, 8, 2, 2, 3, 0, 8, 4, 5, 8, 1, 0, 7, 6, 3, 3, 2, 8, 5, 5, 1, 0, 7, 3, 1, 3, 8, 4, 0, 9, 6, 5, 9, 5, 4, 9, 4, 3, 7, 6, 1, 4, 8, 7, 4, 9, 9, 1, 2, 1, 9, 6

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OFFSET

1,1

COMMENTS

This is the best approximation to Pi using four square roots (with coefficients +/-1) of n < 200000, see also A087477.

LINKS

Table of n, a(n) for n=1..100.

EXAMPLE

3.14159265183290...

MATHEMATICA

RealDigits[N[(Sqrt[20467] - Sqrt[19578] + Sqrt[10177] - Sqrt[9553])/2, 101]] (* Georg Fischer, Apr 03 2020 *)

CROSSREFS