This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A342274 #23 Mar 14 2021 20:35:41 %S A342274 4,8,14,18,18,26,42,42,26,26,46,66,70,74,98,90,42,26,46,66,74,90,138, %T A342274 170,134,90,114,174,194,194,226,190,74,26,46,66,74,90,138,170,138,106, %U A342274 146,226,274,290,346,378,262,122,114,174,210,250,362,474 %N 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. %C A342274 This could be divided by 2 but then it would no longer be compatible with A342272 and A342273. %C A342274 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. %e A342274 Row k=6 of A170899 breaks up naturally into 7 pieces: %e A342274 1; %e A342274 2; %e A342274 4,4; %e A342274 4,8,12,8; %e A342274 4,8,14,18,16,20,28,16; %e A342274 4,8,14,18,18,26,42,42,24,20,36,50,46,50,62,32; %e A342274 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. %e A342274 The penultimate piece matches the sequence for 8 terms. The number of matching terms doubles at each row. %Y A342274 Cf. A151723, A170899, %K A342274 nonn %O A342274 0,1 %A A342274 _N. J. A. Sloane_, Mar 13 2021