A129979 Left border of triangle A131088.

1, 3, 3, 2, 3, 1, 3, 2, 2, 1, 3, 2, 3, 1, 1, 2, 3, 2, 3, 2, 1, 1, 3, 2, 2, 1, 2, 2, 3, 3, 3, 2, 1, 1, 1, 2, 3, 1, 1, 2, 3, 3, 3, 2, 2, 1, 3, 2, 2, 2, 1, 2, 3, 2, 1, 2, 1, 1, 3, 2, 3, 1, 2, 2, 1, 3, 3, 2, 1, 3, 3, 2, 3, 1, 2, 2, 1, 3, 3, 2, 2, 1, 3, 2, 1, 1, 1, 2, 3, 2

Offset

1,2

Links

Table of n, a(n) for n=1..90.

Formula

Inverse Moebius transform of A007427 with changed signs except for A007427(1) = 1; i.e., inverse Moebius transform of (1, 2, 2, -1, 2, -4, 2, 0, -1, -4, ...).

Example

A131088 = (1; 3,1; 3,0,1; 2,3,0,1; ...).

Prog

(PARI) T(n, k) = 2*!(n%k) - if (!(n % k), moebius(n/k), 0); \\ A131088
a(n) =  T(n, 1); \\ Michel Marcus, Feb 26 2022

Crossrefs

Cf. A131088, A051731, A054525, A007427.

Sequence in context: A210851 A120992 A228483 * A274709 A260896 A365711

Adjacent sequences: A129976 A129977 A129978 * A129980 A129981 A129982

Keyword

nonn

Author

Gary W. Adamson, Jun 14 2007

Extensions

More terms from Michel Marcus, Feb 26 2022

Status

approved