A090239 a(n) = A053838(n) + 2 modulo 3.

2, 0, 1, 0, 1, 2, 1, 2, 0, 0, 1, 2, 1, 2, 0, 2, 0, 1, 1, 2, 0, 2, 0, 1, 0, 1, 2, 0, 1, 2, 1, 2, 0, 2, 0, 1, 1, 2, 0, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2, 1, 2, 0, 1, 2, 0, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2, 1, 2, 0, 0, 1, 2, 1, 2, 0, 2, 0, 1, 0, 1, 2, 1, 2, 0, 2, 0, 1, 1, 2, 0, 2, 0, 1, 0, 1, 2, 2, 0, 1, 0, 1, 2

Offset

0,1

Comments

Can construct sequence by starting with 2 and mapping 0->012, 1->120, 2->201 (e.g., 2, 201, 201012120, ...) and looking at n-th digit of a term with sufficient digits.

Links

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

Formula

a(n)=mod(n+a([n/3]), 3), a(0)=2. - Michael Somos, Feb 14 2004

Prog

(PARI) a(n)=if(n<0, 0, 2*(n==0), (n+a(n\3))%3) /* Michael Somos, Feb 14 2004 */

Crossrefs

Sequence in context: A371074 A287104 A190483 * A165276 A035698 A230204

Adjacent sequences: A090236 A090237 A090238 * A090240 A090241 A090242

Keyword

nonn

Author

Philippe Deléham, Feb 04 2004

Status

approved