A220522 Number of toothpicks and D-toothpicks after n-th stage in the D-toothpick "narrow" triangle of the third kind.

0, 1, 3, 7, 11, 15, 19, 26, 34, 38, 42, 50, 62, 70, 78, 91, 107, 111, 115, 123, 135, 151, 167, 187, 211, 223, 231, 247, 275, 291, 307, 332, 364, 368, 372, 380, 392, 408, 424, 446, 478, 504, 524, 548, 588, 620, 660, 701, 749, 769, 777

Offset

0,3

Comments

The structure is essentially one of the oblique wedges of several D-toothpick structures. For more information see A220500. First differs from A194442 at a(47). The first differences (A220523) give the number of toothpicks or D-toothpicks added at n-th stage.

Links

Table of n, a(n) for n=0..50.

Omar E. Pol, Illustration of the structure after 32 stages

Omar E. Pol, Illustration of the structure after 64 stages

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

Index entries for sequences related to toothpick sequences

Crossrefs

Cf. A047999, A139250, A194270, A194700, A194440, A194442, A194444, A220496, A220500, A220523.

Sequence in context: A277675 A220496 A194442 * A220526 A034934 A191151

Adjacent sequences: A220519 A220520 A220521 * A220523 A220524 A220525

Keyword

nonn

Author

Omar E. Pol, Dec 15 2012

Status

approved