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

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 ]
Table[NumberDigit[Surd[n, 4], -1, 2], {n, 120}] (* Harvey P. Dale, Jul 28 2023 *)

Crossrefs

Sequence in context: A011670 A011666 A011669 * A185014 A369036 A354948

Adjacent sequences: A023968 A023969 A023970 * A023972 A023973 A023974

Keyword

nonn,base

Author

N. J. A. Sloane, Olivier Gérard

Status

approved