A108039 Replace each entry 2^i(2j+1) of the triangle in A008280 with i and replace 0's with *'s; then the entries n in the new triangle do not occur beyond diagonal a(n), measured from the left edge and taking the left edge to be diagonal number 1.

2, 4, 4, 4, 8, 8, 8, 8, 10, 12, 12, 16, 16, 16, 16, 16, 18, 20

Offset

0,1

Links

Table of n, a(n) for n=0..17.

V. I. Arnold, Bernoulli-Euler updown numbers associated with function singularities, their combinatorics and arithmetics, Duke Math. J. 63 (1991), 537-555.

Sanjay Ramassamy, Modular periodicity of the Euler numbers and a sequence by Arnold, arXiv:1712.08666 [math.CO], 2017.

Example

3's do not occur beyond the 4th diagonal, so a(3) = 4.
Triangle begins:
       *
      * 0
     0 0 *
    * 0 1 1
   0 0 2 1 *
  * 0 1 1 4 4

Crossrefs

Cf. A008280.

Sequence in context: A225355 A117726 A172307 * A367013 A103228 A076340

Adjacent sequences: A108036 A108037 A108038 * A108040 A108041 A108042

Keyword

nonn,more

Author

N. J. A. Sloane, Jun 01 2005

Extensions

Corrected and extended by Sanjay Ramassamy, Nov 03 2018

Status

approved