A233761 Number of toothpicks or D-toothpicks added at n-th stage in the structure of the D-toothpick "wide" triangle of A233760.

0, 1, 2, 2, 4, 2, 4, 6, 8, 2, 4, 6, 12, 14, 12, 14, 16, 2, 4, 6, 12, 14, 20, 22, 26, 22, 12, 18, 32, 38, 28, 30, 32, 2, 4, 6, 12, 14, 20, 22, 26, 22, 20, 30, 44, 62, 52, 46, 54, 38, 12, 18, 36, 46, 56, 62, 74, 74, 30, 42, 72, 86, 60, 62, 64, 2, 4, 6, 12

Offset

0,3

Comments

Essentially the first differences of A233760.

Links

Table of n, a(n) for n=0..68.

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

Index entries for sequences related to toothpick sequences

Formula

a(2n) = A220521(2n); a(2n+1) = A220521(2n+1) - 2.

Example

Written as an irregular triangle in which the row lengths is A011782 the sequence (starting from 1) begins:
1;
2;
2,4;
2,4,6,8;
2,4,6,12,14,12,14,16;
2,4,6,12,14,20,22,26,22,12,18,32,38,28,30,32;
2,4,6,12,14,20,22,26,22,20,30,44,62,52,46,54,38,12,18,36,46,56,62,74,74,30,42,72,86,60,62,64;
Right border gives A000079.

Crossrefs

Cf. A000079, A011782, A139251, A220501, A220521, A233760, A233763, A233781.

Sequence in context: A233781 A233971 A170905 * A035096 A066675 A219433

Adjacent sequences: A233758 A233759 A233760 * A233762 A233763 A233764

Keyword

nonn,tabf

Author

Omar E. Pol, Dec 16 2013

Status

approved