A285202 A285200 displayed as an irregular triangle read by rows.

1, 1, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 5, 4, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 4, 5, 4, 3, 2, 1

Offset

0,3

Comments

This is Ken Knowlton's elevator sequence A285200, but with an extra 1 each time the elevator returns to (or starts at) the first floor.

Row lengths are A285204. The row maxima are given in A285203 (for n>0).

Links

Table of n, a(n) for n=0..96.

Example

Triangle begins:
1,
1, 2, 1,
1, 2, 3, 2, 1,
1, 2, 3, 2, 1,
1, 2, 3, 4, 3, 2, 1,
1, 2, 3, 2, 1,
1, 2, 3, 4, 3, 2, 1,
1, 2, 3, 2, 1,
1, 2, 3, 4, 3, 2, 1,
1, 2, 3, 2, 1,
1, 2, 3, 4, 5, 4, 3, 2, 1,
...

Crossrefs

Cf. A285200, A285201, A285203, A285204.

Sequence in context: A333267 A236325 A080345 * A004737 A255616 A014600

Adjacent sequences: A285199 A285200 A285201 * A285203 A285204 A285205

Keyword

nonn,tabf

Author

N. J. A. Sloane, May 03 2017

Status

approved