A295560 Same as A161644 except that triangles must always grow outwards.

0, 1, 4, 10, 16, 22, 34, 52, 64, 70, 82, 100, 118, 136, 166, 208, 232, 238, 250, 268, 286, 304, 334, 376, 406, 424, 454, 496, 538, 580, 646, 736, 784, 790, 802, 820, 838, 856, 886, 928, 958, 976, 1006, 1048, 1090, 1132, 1198, 1288, 1342, 1360, 1390, 1432, 1474

Offset: 0

Author

N. J. A. Sloane, Nov 27 2017

Keywords

• nonn

References

• R. Reed, The Lemming Simulation Problem, Mathematics in School, 3 (#6, Nov. 1974), front cover and pp. 5-6. [Describes the dual structure where new triangles are joined at vertices rather than edges.]

Links

• Lars Blomberg, Table of n, a(n) for n = 0..10000
• R. Reed, The Lemming Simulation Problem, Mathematics in School, 3 (#6, Nov. 1974), front cover and pp. 5-6. [Scanned photocopy of pages 5, 6 only, with annotations by R. K. Guy and N. J. A. Sloane]
• N. J. A. Sloane, Illustration of first 7 generations of A161644 and A295560 (edge-to-edge version)
• N. J. A. Sloane, Illustration of first 11 generations of A161644 and A295560 (vertex-to-vertex version) [Include the 6 cells marked x to get A161644(11), exclude them to get A295560(11).]
• N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Crossrefs

Cf. A161644, A161645.

Partial sums of A295559.

Extensions

Terms a(18) and beyond from Lars Blomberg, Dec 20 2017