A051065 a(n) = A004128(n) mod 2.

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

Offset

0,1

References

Letter from Gary W. Adamson concerning Prouhet-Thue-Morse sequence, Nov. 11, 1999.

Links

Table of n, a(n) for n=0..104.

Benoit Cloitre, 3^13 steps of the walk using step: turn +90 degrees if a(n)=0, -90 degrees if a(n)=1

Formula

a(0)=0, a(n) = (n + a(floor(n/3))) mod 2. - Alex Ratushnyak, Aug 17 2012

Prog

(Python)
TOP = 1000
a = [0]*TOP
for n in range(1, TOP):
    print(a[n-1], end=', ')
    a[n] = (n + a[n//3]) % 2
# Alex Ratushnyak, Aug 17 2012
(PARI) a(n)=if(n<1, 0, (a(n\3)+n)%2) \\ Benoit Cloitre, Nov 21 2013

Crossrefs

Cf. A004128, A051066, A051067, A051069.

Sequence in context: A257800 A284772 A051069 * A091445 A091446 A341256

Adjacent sequences: A051062 A051063 A051064 * A051066 A051067 A051068

Keyword

nonn,easy

Author

N. J. A. Sloane, Gary W. Adamson

Extensions

More terms from James A. Sellers, Dec 11 1999

Status

approved