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A173458
a(n) = A173457(n+1)/2.
4
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
1,1
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
EXAMPLE
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)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Feb 18 2010
EXTENSIONS
a(13)-a(65) from Lars Blomberg, Apr 22 2013
STATUS
approved