A161421 First differences of A161420.

0, 1, 2, 2, 2, 4, 8, 6, 6, 8, 12, 8, 10, 10, 20, 18, 10, 16, 20, 8

Offset: 0

Author

Omar E. Pol, Jun 10 2009, Dec 12 2010

Keywords

• more
• nonn

Comments

Number of V-toothpicks added at the n-th stage to the V-toothpick structure of A161420. See also A161206 and A161207.

Also it appears a(n) is also the number of toothpicks and D-toothpicks added at n-th stage to the H-toothpick structure of A161420. See also A182838 and A182839.

Links

• David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]
• N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
• Index entries for sequences related to toothpick sequences

Crossrefs

Cf. A139251, A161206, A161207, A161420, A161422, A182633, A182838, A182839.