A244362 Total number of toothpicks after n-th stage in the toothpick structure of the symmetric representation of sigma in the first quadrant (without the axes x and y).

2, 6, 12, 20, 28, 40, 50, 66, 82, 102, 116, 140, 156, 182, 208, 240, 260, 296, 318, 358, 394, 432, 458, 506, 540, 584, 628, 684

Offset

1,1

Comments

Partial sums of A244363.

Links

Table of n, a(n) for n=1..28.

Formula

a(n) = 2*A244360(n).

a(n) = A244370(n)/4. - Omar E. Pol, Oct 18 2014

Example

Illustration of the structure after 7 stages (Contains 50 toothpicks):
.
.    _ _ _ _
.    _ _ _ _|
.    _ _ _  |_
.    _ _ _|   |_ _
.    _ _  |_ _  | |
.    _ _|_  | | | |
.    _  | | | | | |
.     | | | | | | |
.
.     1 2 3 4 5 6 7
.

Crossrefs

Cf. A000203, A237270, A237271, A237593, A244360, A244361, A244363, A244370, A244371.

Sequence in context: A120344 A031426 A258633 * A175967 A254949 A034100

Adjacent sequences: A244359 A244360 A244361 * A244363 A244364 A244365

Keyword

nonn,more

Author

Omar E. Pol, Jun 26 2014

Extensions

More terms from Omar E. Pol, Oct 18 2014

Status

approved