A161432 a(n) = A161431(n)/3.
3, 8, 8, 22, 8
Offset: 1
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.
Contribution from _Omar E. Pol_, Jun 18 2009: (Start) May be written as a triangle: 1, 3, 3, 9, 3,9, 9,21,9,9, 9,21,15,21,27,51,27,9, 9,21,15,21,27,51,33,21,27,51,51,57,69,117,81,21, 9,21,15,21,27,51,33,21,27,51,51,57,69,117,87,33,27,51,51,57,75,129,117,75,69,117,135,141,171,279,231,69; Rows converge to A161326. (End) Contribution from _Omar E. Pol_, Dec 18 2012: (Start): Also this sequence may be written as another triangle (according to the structure of triangle A151710): 1; 3; 3, 9; 3, 9,9,21; 9, 9,9,21,15,21,27,51; 27, 9,9,21,15,21,27,51,33,21,27,51,51,57,69,117; 81,21,9,21,15,21,27,51,33,21,27,51,51,57,69,117,87,33,27,51,51,57,75,129,117,75,69,117,135,141,171,279; (End)
YTPFunc[lis_, step_] := With[{out = Extract[lis, {{1, 2}, {2, 1}, {-1, -1}}], in = lis[[2, 2]]}, Which[in == 1, 3, in == 0 && Count[out, 1] >= 2, 2, in == 0 && Count[out, 1] == 1, 1, True, in]]; A160121[n_] := Count[CellularAutomaton[{YTPFunc, {}, {1, 1}}, {{{1}}, 0}, {{{n}}}], 1, 2] (* JungHwan Min, Jan 28 2016 *)
A160121[n_] := Count[CellularAutomaton[{13390417258775213635414055181254541831894674613399006361662885886563211940509571858857491972104491013971547937418035084866785430974106432144737472376143620, 4, {{-1, 0}, {0, -1}, {0, 0}, {1, 1}}}, {{{1}}, 0}, {{{n}}}], 1, 2] (* JungHwan Min, Jan 28 2016 *)
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