A342274 Consider the k-th row of triangle A170899, which has 2^k terms; discard the first quarter of the terms in the row; the remainder of the row converges to this sequence as k increases.

4, 8, 14, 18, 18, 26, 42, 42, 26, 26, 46, 66, 70, 74, 98, 90, 42, 26, 46, 66, 74, 90, 138, 170, 134, 90, 114, 174, 194, 194, 226, 190, 74, 26, 46, 66, 74, 90, 138, 170, 138, 106, 146, 226, 274, 290, 346, 378, 262, 122, 114, 174, 210, 250, 362, 474

Offset: 0

Author

N. J. A. Sloane, Mar 13 2021

Keywords

• nonn

Comments

This could be divided by 2 but then it would no longer be compatible with A342272 and A342273.

It would be nice to have a formula or recurrence for any of A170899, A342272-A342278, or any nontrivial relation between them. This might help to understand the fractal structure of the mysterious hexagonal Ulam-Warburton cellular automaton A151723.

Examples

			Row k=6 of A170899 breaks up naturally into 7 pieces:
1;
2;
4,4;
4,8,12,8;
4,8,14,18,16,20,28,16;
4,8,14,18,18,26,42,42,24,20,36,50,46,50,62,32;
3,6,11,13,13,21,33,29,17,21,37,51,51,57,77,61,21,15,27,34,36,52,80,80,44,38,62,81,58,73,63,0.
The penultimate piece matches the sequence for 8 terms. The number of matching terms doubles at each row.
		

Crossrefs

Cf. A151723, A170899,