A140399 Numbers n such that A140397(n) = 1.

1, 4, 9, 12, 14, 17, 20, 22, 25, 30, 33, 35, 38, 41, 43, 46, 48, 51, 54, 56, 59, 64, 67, 69, 72, 75, 77, 80, 85, 88, 90, 93, 98, 101, 103, 106, 109, 111, 114, 119, 122, 124, 127, 130, 132, 135, 140, 143, 145, 148, 153, 156, 158, 161, 164, 166, 169, 174, 177, 179, 182

Offset

1,2

Comments

Alternatively, those n for which no block of length 3n in the Fibonacci word A003849 forms an abelian cube (that is, a block of the form x x' x'' where x' and x'' are permutations of x). Proved with the Walnut theorem prover. - Jeffrey Shallit, Jun 23 2021

Links

Table of n, a(n) for n=1..61.

Crossrefs

Sequence in context: A272933 A367929 A243650 * A312849 A161544 A179395

Adjacent sequences: A140396 A140397 A140398 * A140400 A140401 A140402

Keyword

nonn

Author

Fred Lunnon, Jun 20 2008

Extensions

More terms from Max Alekseyev, Apr 24 2010

Status

approved