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A161334
Numbers of snowflake sequence, divided by 2: a(n) = A161330(n)/2.
3
0, 1, 4, 7, 10, 19, 22, 31, 40, 49, 64, 73, 88, 109, 112, 121, 130, 145, 172, 187, 226, 247, 274, 313, 334, 367, 406, 415, 436, 457, 484, 529, 562, 625, 670, 715, 766, 799, 838, 883, 928, 973, 1000, 1033, 1090, 1129, 1192, 1255, 1306, 1357, 1426, 1477
OFFSET
0,3
COMMENTS
Also number of E-toothpicks after n-th stage on the semi-infinite triangular grid. A161332 (the first differences) gives the number of E-toothpicks added at n-th stage. - Omar E. Pol, Jan 07 2014
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, A single E-toothpick
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Jun 07 2009
EXTENSIONS
More terms from Omar E. Pol, Jan 07 2014
STATUS
approved