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A221208 Decimal expansion of the Borwein integral with 8 sinc functions. 1
1, 5, 7, 0, 7, 9, 6, 3, 2, 6, 7, 7, 1, 7, 9, 6, 0, 4, 6, 5, 0, 5, 8, 4, 0, 8, 9, 4, 2, 4, 6, 4, 9, 5, 8, 5, 4, 7, 5, 0, 6, 5, 9, 3, 1, 8, 3, 8, 7, 5, 3, 2, 5, 9, 5, 9, 8, 0, 2, 2, 7, 5, 8, 2, 3, 5, 4, 7, 7, 6, 9, 6, 2, 7, 6, 6, 9, 2, 6, 3, 9, 1, 0, 7, 0, 4, 9, 6, 6, 6, 1, 7, 9, 3, 8, 6, 3, 4, 7, 3, 4, 0, 5, 0, 3 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The difference from Pi/2 (A019669) is approximately 0.231006*10^(-10).

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Eric Weisstein's MathWorld, Borwein Integrals

Wikipedia, Borwein integral

FORMULA

Equals 467807924713440738696537864469/935615849440640907310521750000*Pi. - Alois P. Heinz, Feb 28 2020

EXAMPLE

1.57079632677179604650584089424649585475065931838753259598...

MATHEMATICA

Integrate[Product[Sinc[x/(2*k+1)], {k, 0, 7}], {x, 0, Infinity}] // RealDigits[#, 10, 105]& // First

CROSSREFS

Cf. A000796, A019669, A068214, A068215, A144616.

Sequence in context: A195793 A216545 A216547 * A085679 A019669 A088394

Adjacent sequences:  A221205 A221206 A221207 * A221209 A221210 A221211

KEYWORD

cons,nonn,easy

AUTHOR

Jean-Fran├žois Alcover, Feb 21 2013

STATUS

approved

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Last modified November 29 18:41 EST 2021. Contains 349416 sequences. (Running on oeis4.)