A233764 Number of toothpicks and D-toothpicks after n-th stage in a D-toothpick "wide" triangle (see Comments lines for definition).

0, 1, 3, 5, 9, 11, 15, 21, 29, 31, 35, 41, 51, 61, 69, 83, 99, 101, 105, 111, 121, 131, 141, 159, 183, 201, 209, 223, 245, 271, 287, 317, 349, 351, 355, 361, 371, 381, 391, 409, 433, 451, 461, 479, 507, 545, 575, 625, 679, 713, 721, 735, 757, 783

Offset

0,3

Comments

The D-toothpicks placed in northwest or northeast direction both are prohibited. Note that due this rule there are substructures with broken symmetry, for instance a(44) = 507, not 509. For another version without broken symmetry see A233780.

A233765 (the first differences) gives the number of toothpicks or D-toothpicks added at n-th stage.

First differs from A169780 at a(24).

First differs from A233970 at a(25).

First differs from A233780 at a(44).

Links

Table of n, a(n) for n=0..53.

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

Index entries for sequences related to toothpick sequences

Crossrefs

Cf. A139250, A169780, A220500, A220520, A231348, A233765, A233780, A233970.

Sequence in context: A261141 A283594 A339173 * A233780 A233970 A169780

Adjacent sequences: A233761 A233762 A233763 * A233765 A233766 A233767

Keyword

nonn

Author

Omar E. Pol, Dec 16 2013

Status

approved