login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A299476
Toothpick sequence on triangular grid with word "abcb".
7
0, 1, 3, 7, 13, 21, 27, 39, 49, 57, 69, 87, 111, 135, 155, 185, 203, 211, 223, 241, 265, 293, 321, 367, 405, 453, 499, 567, 633, 701, 751, 823, 859, 869, 881, 899, 923, 951, 979, 1025, 1067, 1119, 1179, 1259, 1347, 1439, 1529, 1647, 1731, 1805
OFFSET
0,3
COMMENTS
a(n) gives the number of toothpicks of length 2 in the structure after n-th stage.
A299477 (the first differences) gives the number of toothpicks added at n-th stage.
For more information about the "word" of a cellular automaton see A296612.
CROSSREFS
Cf. A299477 (first differences), A296612.
Cf. A160120 (word "a"), A139250 (word "ab"), A296510 (word "abc"), A299478 (word "abcbc").
Sequence in context: A073896 A299478 A355310 * A077853 A256588 A025721
KEYWORD
nonn,more
AUTHOR
Omar E. Pol, Feb 11 2018
STATUS
approved