A082561 a(1)=1, a(n)=3*a(n-1) if n is not a multiple of 3, or a(n)=a(n/3)+1 if n is a multiple of 3.

1, 3, 2, 6, 18, 4, 12, 36, 3, 9, 27, 7, 21, 63, 19, 57, 171, 5, 15, 45, 13, 39, 117, 37, 111, 333, 4, 12, 36, 10, 30, 90, 28, 84, 252, 8, 24, 72, 22, 66, 198, 64, 192, 576, 20, 60, 180, 58, 174, 522, 172, 516, 1548, 6, 18, 54, 16, 48, 144, 46, 138, 414, 14, 42, 126, 40, 120

Offset

1,2

Comments

b(1)=1, b(n)=3*b(n/3) if n is a multiple of 3, or b(n)=b(n-1)+1 if n is not a multiple of 3 produces the sequence 1, 2, 3, 4, ...

Links

Table of n, a(n) for n=1..67.

Prog

(PARI) a(n)=if(n<2, 1, if(n%3, 3*a(n-1), 1+a(n/3)))

Crossrefs

Sequence in context: A285457 A007812 A276225 * A268642 A110768 A140230

Adjacent sequences: A082558 A082559 A082560 * A082562 A082563 A082564

Keyword

nonn

Author

Benoit Cloitre, May 04 2003

Status

approved