A278597 One half of A278481.

1, 2, 2, 2, 3, 2, 2, 3, 3, 2, 2, 3, 3, 3, 2, 2, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2

Offset

1,2

Comments

Apart from the left border and the right border, the rest of the elements are 3's.

Links

Table of n, a(n) for n=1..105.

Formula

a(n) = A278481(n)/2.

Example

The sequence written as a triangle begins:
                      1;
                    2,  2;
                  2,  3,  2;
                2,  3,  3,  2;
              2,  3,  3,  3,  2;
            2,  3,  3,  3,  3,  2;
          2,  3,  3,  3,  3,  3,  2;
        2,  3,  3,  3,  3,  3,  3,  2;
      2,  3,  3,  3,  3,  3,  3,  3,  2;
    2,  3,  3,  3,  3,  3,  3,  3,  3,  2;
  ...

Crossrefs

Row sums give A016777.

Left border gives A040000, the same as the right border.

Middle column gives A122553.

Every diagonal that is parallel to any of the borders gives the elements greater than 1 of A158799.

Cf. A278481.

Sequence in context: A160493 A053760 A223942 * A138789 A129654 A116504

Adjacent sequences: A278594 A278595 A278596 * A278598 A278599 A278600

Keyword

nonn,tabl

Author

Omar E. Pol, Nov 23 2016

Status

approved