A023971 - OEIS

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A023971

First bit in fractional part of binary expansion of 4th root of n.

0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(n) = 0 if k^4 <= n <= k^4 + 2*k^3 + (3*k^2+k)/2,

= 1 if k^4 + 2*k^3 + (3*k^2+k)/2 < n < (k+1)^4. - Robert Israel, Aug 18 2014

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

[seq(floor(2*n^(1/4)) mod 2, n=1..1000)]; # Robert Israel, Aug 18 2014

MATHEMATICA

Array[ Function[ n, RealDigits[ N[ Power[ n, 1/4 ], 10 ], 2 ]// (#[ [ 1, #[ [ 2 ] ]+1 ] ])& ], 110 ]