A173523 1+A053735(n-1), where A053735 is the sum-of-digits function in base 3.

1, 2, 3, 2, 3, 4, 3, 4, 5, 2, 3, 4, 3, 4, 5, 4, 5, 6, 3, 4, 5, 4, 5, 6, 5, 6, 7, 2, 3, 4, 3, 4, 5, 4, 5, 6, 3, 4, 5, 4, 5, 6, 5, 6, 7, 4, 5, 6, 5, 6, 7, 6, 7, 8, 3, 4, 5, 4, 5, 6, 5, 6, 7, 4, 5, 6, 5, 6, 7, 6, 7, 8, 5, 6, 7, 6, 7, 8, 7, 8, 9, 2, 3, 4, 3, 4, 5, 4, 5, 6, 3, 4, 5, 4, 5, 6, 5, 6, 7, 4, 5, 6, 5, 6, 7, 6, 7, 8, 3, 4, 5, 4, 5, 6, 5, 6, 7, 4, 5, 6

Offset

1,2

Comments

A053735 can be obtained as 0 followed by the first 2 terms of this sequence, followed by the first 6 terms, followed by the first 18 terms, ..., followed by the first 2*3^n terms, etc.

Similar observations are possible for: A063787 (base-2 case), and generic comments have been gathered in A173525 (base-5 case).

Fixed point of morphism 1->123, 2->234, 3->345 etc. (start with 1).

Links

Table of n, a(n) for n=1..120.

Example

If written as a triangle, begins:
1,
2,3,
2,3,4,3,4,5,
2,3,4,3,4,5,4,5,6,3,4,5,4,5,6,5,6,7,
2,3,4,3,4,5,4,5,6,3,4,5,4,5,6,5,6,7,4,5,6,5,6,7,6,7,8,...

Crossrefs

Cf. A000120, A053735, A063787, A173524 - A173529.

Sequence in context: A240834 A256993 A348192 * A199323 A156549 A275868

Adjacent sequences: A173520 A173521 A173522 * A173524 A173525 A173526

Keyword

base,nonn

Author

Omar E. Pol, Feb 20 2010

Status

approved