A173458 a(n) = A173457(n+1)/2.

4, 6, 2, 14, 18, 2, 14, 18, 6, 42, 54, 2, 14, 18, 6, 42, 54, 6, 42, 54, 18, 126, 162, 2, 14, 18, 6, 42, 54, 6, 42, 54, 18, 126, 162, 6, 42, 54, 18, 126, 162, 18, 126, 162, 54, 378, 486, 2, 14, 18, 6, 42, 54, 6, 42, 54, 18, 126, 162, 6, 42, 54, 18, 126, 162

Offset: 1

Author

Omar E. Pol, Feb 18 2010

Keywords

• nonn
• tabf

Examples

			From Omar E. Pol, Apr 22 2013 (Start):
When written as an irregular triangle begins:
4,6;
2,14,18;
2,14,18,6,42,54;
2,14,18,6,42,54,6,42,54,18,126,162;
2,14,18,6,42,54,6,42,54,18,126,162,6,42,54,18,126,162,18, 126,162,54,378,486;
2,14,18,6,42,54,6,42,54,18,126,162,6,42,54,18,126,162,...
(End)
		

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

Crossrefs

Cf. A173456, A173457, A173459, A173462.

Extensions

a(13)-a(65) from Lars Blomberg, Apr 22 2013