A255913 Decimal expansion of A such that y = A*x^2 cuts the first quadrant of the unit circle into two equal areas.

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

Offset

1,1

Comments

A is found by solving the equation A*x^3/3 = Pi/4 - arcsin(x), where x = sqrt( (sqrt(4*A^2+1)-1)/(2*A^2) ).

Links

Table of n, a(n) for n=1..108.

Example

2.352230153915807634852772512117541580739215424880243089235782...

Prog

(PARI) solve(A = 2, 3, A/3*(sqrt((sqrt(4*A^2+1)-1)/(2*A^2)))^3 - Pi/4 + asin(sqrt((sqrt(4*A^2+1)-1)/(2*A^2)))) \\ Michel Marcus, Mar 11 2015

Crossrefs

Sequence in context: A205387 A365424 A060441 * A065996 A133906 A317358

Adjacent sequences: A255910 A255911 A255912 * A255914 A255915 A255916

Keyword

nonn,cons,easy

Author

Derek Orr, Mar 10 2015

Status

approved