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A129979
Left border of triangle A131088.
1
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
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
KEYWORD
nonn
AUTHOR
Gary W. Adamson, Jun 14 2007
EXTENSIONS
More terms from Michel Marcus, Feb 26 2022
STATUS
approved