This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A285395 Start with a single cell at coordinates (0, 0, 0), then iteratively subdivide the grid into 3 X 3 X 3 cells and remove the cells whose sum of modulo 2 coordinates is 1; a(n) is the number of cells after n iterations. 8
 1, 15, 249, 4371, 78693, 1431735, 26159649, 478778379, 8768545197, 160633207887, 2942987702217, 53921188767939, 987955842925365, 18101659807680423, 331665550405417905, 6076909441961837115, 111343619823563404797, 2040083652208572498111, 37379255055440801236953 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Cell configuration converges to a fractal with dimension 2.647... LINKS Peter Karpov, InvMem, Item 26 Peter Karpov, Illustration of initial terms (n = 1..4) FORMULA a(0) = 1, a(1) = 15, a(2) = 249, a(n) = 28*a(n-1) - 195*a(n-2) + 324*a(n-3). G.f.: (1-13*x+24*x^2)/(1-28*x+195*x^2-324*x^3). MATHEMATICA LinearRecurrence[{28, -195, 324}, {1, 15, 249}, 19] CROSSREFS Cf. A285396, A285394, A285393, A285392, A285391. Sequence in context: A273624 A223424 A218806 * A093147 A218192 A066410 Adjacent sequences:  A285392 A285393 A285394 * A285396 A285397 A285398 KEYWORD nonn AUTHOR Peter Karpov, Apr 19 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 13 17:50 EST 2018. Contains 317149 sequences. (Running on oeis4.)