A220514 D-toothpick sequence of the third kind starting with a X-shaped cross formed by 4 D-toothpicks.

0, 4, 12, 28, 44, 60, 92, 136, 168, 184, 216, 280, 376, 440, 520, 620, 684, 700, 732, 796, 892, 1020, 1164, 1332, 1508, 1588, 1684, 1860, 2116, 2276, 2452, 2664, 2792, 2808, 2840, 2904, 3000, 3128, 3272, 3448, 3656, 3824, 4016, 4272, 4676, 4992

Offset

0,2

Comments

This is a toothpick sequence of forking paths to 135 degrees. The sequence gives the number of toothpicks and D-toothpicks in the structure after n-th stage. A221528 (the first differences) give the number of toothpicks or D-toothpicks added at n-th stage. It appears that the structure has a fractal (or fractal-like) behavior. For more information see A194700.

First differs from A194434 at a(13).

Links

Table of n, a(n) for n=0..45.

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to toothpick sequences

Formula

a(n) = 4*A220524(n).

Crossrefs

Cf. A139250, A194270, A194700, A194434, A220500, A220520, A220522, A221528.

Sequence in context: A194432 A220512 A194434 * A301005 A178571 A278211

Adjacent sequences: A220511 A220512 A220513 * A220515 A220516 A220517

Keyword

nonn

Author

Omar E. Pol, Dec 15 2012

Status

approved